ra. cassida, 49. Convex, longitudinally ribbed, and striated diated towards the base, and surrounded with 2 brown transversely, with the summit recurved; base roundish, rings. Martini, i. t. 7. f. 55. diated in pairs, and the margin yellowislı. w. Indies. tranque 50. Ovate, thin, pellucid, with fine crowded striæ; Chem. x. t. 168. f. 1619. ; . barica. chesnut with white scales, within milk-white ; with a 70. Entire, acute, smooth, glabrous. Indian and testudina. brown spot at the bottom, and azure spot on the crown. North seas. Martini, i. t. 6. f. 45 to 48. ria. Tranquebar. Lister, t. 530. f. 8. 71. Entire, ovate, striated; crown obtuse, nearly testudingmammila- 51. Conical, subpellucid, finely striated longitudi- central; 14 lines long. Greenland seas. ; Chem. X.lis. ris. nally, and the summit reflected ; base oblong, and the t. 168. f. 1614 and 1615. margin entire. Mediterranean. Lister, t. 537. f. 17. 72. Entire, oval, oblong, striated, smooth; com-compressa leucopleu- 52. Striated, entire, alternately black and white: pressed on the back ; 14 inches long. India. Lister, . 1 inch long. West Indies. Lister, t. 539. f. 22. t. 541. f. 25. tricarina- 53. Substriated, with 3 ribs on the forepart ; 21 73. Conical, elevated, with about 100 narrow longi-afra. ta. inches high. New Zealand. Born, t. 18. f. 6. tudinal ribs ; summit obtuse, glabrous, and central. pectinata. 54. Entire, ovate, with wrinkled, slightly branched Island of Goree. Martini, i. t. 5. f. 34. striæ ; crown nearly central ; 2 inches long. Medi. 74. Entire, conic, with 50 obtuse striæ; 3 inches rustica. long. Portugal. Lister, t. 537. f. 20. fusco:lutca 55. Convex, oval-oblong, submembranaceous, with 75. Conical, convex towards the base, with longitu- jamaicen longitudinal strice, wbich are alternately larger, and dinal striæ, and distant transverse ridges; base round- sis. 76. Qval, entire, striated ; black brown radiated stellifera. lutea. 56. Entire, oval, convex, striated, with a submar. with white; within silvery. Friendly islands and New ginal, reflected, mucronate crown ; size of a melon seed. Zealand. Chem. x. t. 168. f. 1617. 77. Entire, ovate, obtuse, with 39 cinereous, fli-fusca. perversa. 57. Oblong, horny, very thin, pellucid, glabrous, form, elevated striæ. Straits of Magellan. Martini, , 78. Depressed, thick, with remote decussated striæ surinomlacustris. 58. Entire, oval, membranaceous, with a central, towards the base, and the summit smooth and central ; ensis. mucronate, reflected crown ; 1{ to 2 lines long. Fresh base nearly oval; inside yellow. Surinam. Martini, i. t. 7. f. 50. oblonga.j 59. Membranaceous, brittle, slightly contracted in 79. Entire, striated, with a submucronate, erect notata. the middle, with the summit pointed and obliquely re- crown; within white, with a black, heart-shaped spot, X. vig. 25. f. c and d. 8o. Entire, oval, subconvex; brown, with a white cruciata. entire. cross ; 1 inch long. Schroeter, ii. t. Se f. 7. 81. Entire, conic.compressed, with reticulated veins. reticulata. lævis. 60. Subconical, smooth, and diverging longitudinal Mediterranean. Schroeter, ii. t. 5. f. 7. lines, and the summit nearly marginal; base subovate. 82. Oval, with crowded longitudinal elevated dotted cca. England. Montagu, t. 13. f. 8. strive, and the summit acute and erect. Drobach in radians. 61. Oval, pellucid, much depressed, striated longi- Norway. Muller Zool. Don. i. t. 12. f. 1 to 3. tudinally, and radiate with blackish spots. New Zea- 83. Oval, very entire, with pale purplish longitudi- virginea. Jand. Chem. x. t. 168. f. 1618. nal rays, and the summit nearly marginal. Britain and areolata. 62. Pyramidal, reddish gray, with thin, circular Norway. Don. t. 21. f. 2. striæ crossed by longitudinal ones ; crown violet. Straits 84. Oblong-oval; very entire ; finely striated lon- tesselato. of Magellan. Martini, i. t. 5. f. 41. gitudinally, whitish, tesselated with red spots. Nor- . flammea. 63. Ovate, with fine annulated striæ, reddisb grey, way. Muller Zool. Don. i. t. 12. f. 6 and 7. with undulated brown_rays; crown acute, central; 85. Oval-oblong, with minule, somewhat decussated fuulva. in Norway. Muller Zool. Don. i. t. 24. f. 1 to 3. indica. 64. Reddish grey, with radiated striæ, glabrous, 86. Oblong, depressed, with the posterior margin ambigua. narrower on one side ; crown acute, sinooth, surrounded rounded, and the anterior truncated; summit nearly 33 87. Entire, oval, pellucid, depressed, striated, horny, radians. suring. 65. Thick, subovate, yellowish, with black rays, and and radiated with black spots. New Zealand. Chem. mensis. longitudinal, unequal striæ ; and surrounded with knot x. t. 168. f. 1618. ty belts ; crown obtuse, smooth, white. Surinam. 88. Entire, roundish, diaphanous ; depressed, with umbellata.. Martini, i. t. 7. f. 5o. yellowish rays within ; crown pale yellow ; margin very vitellina. 66. Ovate, yellow; base unequally striated; crown acute; 4 inches long. Indian ocean. Chem. x. t. 169. whitisii, obtuse. Martini, i. t. 7. f. 51. f. 1645. lævigata. 67. Ovate, yellow, within bluish white, with oblique ****** With a marginal fissure. flattened striæ, alternately thicker and thinner; crown wbite, smooth, polished. Martini, i. t. 7. f. 54. • 89. Oval, conic, with reticulated striæ; cleft on the fissura. punctulata 68. Rounded, white, with many coloured dots, ca. fore-part ; crown. recuryed; } inch long. European and & incisa. fissurata and Barbary coasts, Devonshire. Martini, i. t. 12. f. 109 and 110. 90. Oval, rather depressed, cancellated, with a broad marginal fissure, and the summit recurved. Falkland islands. Chem. xi. t. 197. f. 1925 and 1926. 91. Oval, depressed, with crowded longitudinal striæ, and a short marginal fissure. New Zealand. Chem. xi. t. 197. f. 1929 and 1930. ******* With a perforated summit. noachina. 92. Conical, longitudinally striated, and the summit recurved, with a rhomboidal perforation, extending towards the anterior margin. Norway and Britain. Montagu, t. 13. f. 10. pustula. 93. Oval, gibbous, convex, with reticulated striæ; margin crenated; perforation near the posterior margin. Mediterranean and Indian seas. Lister, t. 528. græca. atricapilla nodosa. perforata. caffra. pileolus. scutellum. picta. nimbosa. nubecula. porphyro zonias. macrochis ma. 61 Dentalium. f. 30. 94. Ovate, convex, reticulated; crown not much elevated; perforation oblong; margin crenulated; length inch. Foreign specimens 1 inch. European seas, Sandwich. Don. i. t. 21. f. 3. 95. Ovate, cancellated, with the longitudinal ribs nodulous and alternately smaller; summit somewhat lateral, and the inner margin entire. Barbadoes. Lister, t. 528. f. 5. 96. Oval, subconical, with elevated, strongly tuber. culated ribs, and the summit nearly central; margin crenated. Barbadoes. Lister, t. 528. f. 6. 97. A little convex, transversely wrinkled; brownish, with straw-coloured rays and spots; striæ longitudinal, and alternately larger and scaly; 1 inch long. Barbadoes. Lister, t. 528. f. 7. 98. Ovate, compressed, striated; finely annulated, and radiated with black; bottom milk-white; perforation nearly central. Cape of Good Hope. Martini, i. t. 11. f. 95. 99. Oblong, with longitudinal striæ, and the sides compressed; perforation circular and submarginal. Chem. xi. t. 197. f. 1922. 100. Repand on each side, compressed; perforation radiated with grooves; from 1 to 1 inch long. Falkland islands. Schroeter, ii. t. 6. f. 11. 90. IOI. Ovate, with concentrical elevated belts, and alternately white and violet longitudinal rays; perforation oval. Magellan straits. Martini, i. t. 11. f. 102. Ovate, striated, rugged, brown; perforation oblong; 2 inches long. Mediterranean and Atlantic. America. Martini, i. t. 11. f. 91 and 92. 103. Subovate, rugged, white radiated with red; slightly striated; perforation ovate. Mediterranean. Lister, t. 529. f. 22. 104. Oblong, compressed, unequally striated; white, with 5 purple, interrupted belts; greenish white within; perforation minute, surrounded on the inside with a red circle. North America. Martini, i. t. 12. f. 102 and 103. 105. Ovate-oblong, slightly striated, and the sides somewhat compressed; perforation very long, and widened at the posterior end. Japan. Chem. xi. t. 197. f. 1923 and 1924. Gen. 33. DENTALIUM, Tooth-shell. Gen. Char.-The animal a terebella; shell univalve, tubular, straight or slightly curved, with an undivided cavity, open at both ends. SPECIES. 1. With 10 ribs, slightly curved and striated; 4 elephantiinches long. Indian and European seas. Lister, t.num. 547. upper f. 1. 2. Straight, doubly or triply striated, and annulated. rectum. E. Indies. Martini, i. t. 1. f. 4. A. 3. With 10 ribs, smooth, and slightly curved. In-aprinum. dian seas. Martini, i. t. 1. f. 4. B. 4. With 8 ribs and 8 striæ, pointed; green, tipped striatum. with white. Sicilian seas. Lister, t. 547. lower fig. 5. With 20 striæ, slightly curved, interrupted; red, dentalis. tipt, with white. Mediterranean. Rumphius, t. 41. f. 6. 6. Round, slightly curved; smooth, glossy, taper-entalis. ing to a small point; pervious; 1 inch long. Indian and European shores; western coasts of England. Don. ii. t. 48. corneum. 7. Round, slightly curved, interrupted, opaque; inch long. African ocean. Schroeter, ii. t. 6. f. 16. 8. Round, slightly curved, continued, with crowded, politum. annular striæ; 1 inch long. Indian and European seas. Martini, i. t. 1. f. 3. A. 9. White, smooth, round, slightly curved, with re-eburneum. mote rings. India. Gmelin. 10. Finely striated, slightly curved; grey, with fasciatum. darker bands; thickness of a crow quill. Sicily. Martini, i. t. 1. f. 3. B. II. Subpellucid, subarcuated, tapering to a small gadus. point; pervious, contracting a little towards the larger end; white, glossy, and smooth. British channel; called by the mariners hake's tooth. It is frequently brought up with the sounding line. Montagu, t. 14. Gen. 34. SERPULA, Worm-Shell. Gen. Char.-The animal a terebella: shell, univalve, tubular, generally adhering to other substances; often separated internally by entire divisions at unequal distances. SPECIES. Scrpula. 1. Suborbicular; umbilicated; convex, with radi-stellaris. ated wrinkles. Greenland, on Sertularia. 2. Regular, oval, loose, glabrous, not larger than seminu3 N 2 a lum. * * a grain of sand. Adriatic and Red seas; and is some• to 3 whirls, with a central tip. Goree. Martini, i. t. 3. f. 20. A. B. incurvata, 3. Straight, with 3 close whirls at the smaller end; 26. Suboctangular, cancellated, and irregularly spi- volvox. minute. Sandwich. Walker, f. 12. ral. E. Indies. Martini, i. t. 2. f. 14. planorbis. 4. Orbicular, regular, flat, equal; resembles a round 27. Roundish, somewhat spiral, with a longitudinal, anguina. scale; adheres to shells. jointed cleft. Indian ocean. Lister, t. 548. f. 2. cereolus. 5. Long, narrow, round, smooth, yellowish ; many 28. Angular, muricated, with a longitudinal, subarti- muricata. times twisted. America. Martini, i. t. 3. f. 20. E. i culated fissure. Indian ocean. Martini, i. t. 2. f. 8. spirillum. * 6. Regular, spiral, orbicular; whirls round, gra- 29. Subcylindrical, with annular contractions, and annularis. dually decreasing. Found in the ocean, on zoophytes, , an obsolete longitudinal fissure. Martini, i. t. 2. f. 30. Conic, spirally twisted, yellowish, with brown orn ucominuta. 7. Regular, spiral, orbicular, with the wbirls re- bands; the middle round and twisted ; aperture orbi-piæ. versed ; taper, and transversely wrinkled. Britain. cular. Mauritius island. Chem. xi. t. 211. f. 202 and 203. spirorbis. * 8. Regular, spiral, orbicular; whirls slightly chan- 31. Round, with decussated striæ, slightly wrinkled, decussata. nelled above and inwardly, and diminishing gradually flexuous, red; within smooth, white. Barbadoes. Lis li towards the centre. Found in most seas, adhering to ter, t. 547. f.4. . fuci. Shores of Britain. Don. t. 9. 32. Round, tapering, curved, wrinkled; 2 to 3 vermicu. riquetra. 9. Strong, opaque, irregularly twisted and contort- inches long. European seas, coasts of Britain. Don.laris. ed; triangular; } to 1 inch long. Found in the t. 95. The animal wbich inhabits this shell is of a ocean, adhering to marine substances, stones, and the bright scarlet colour, and is furnished with elegant bottoms of ships. Coasts of Britain. Don. t. 95. feathered tentacula, from the midst of wbicb arises a intricata. * 10. Filiform, rough, and intricately twisted; green- trumpet-shaped tube, and a lesser simple one. ish white, a little rugged and coarse. European and 33. Taper, subulated, and flexuous, with the larger tubularia. Indian seas; shores of Britain, on shells. end detached and ascending. Devonshire and Shetcarinata. 11. Regular, spiral, with the outer whirl rising into land islands. a carinated ridge on the top. Salcombe Bay, De- 34. White, round, subulate, straight, and toothed denticuvonshire. at the sides ; with a longitudinal glabrous, rib in the lata. granulata. * 12. Round, spiral, glomerated ; 3 elevated ribs on middle ; tip glabrous, a little incurved ; * inch long. the upper side ; size of a coriander seed. North seas, Found in the lepas tintinnabulum. West Indies. 35. Watering-pot; round, straight, taper, with a aquaria. cancellata. 13. Spiral, glomerated, with three grooves, the lower dilated, radiated, larger extremity; the dise is cover interrupted by transverse ribs; aperture 2-toothed. ed with cylindrical pores ; 3 to 5 inches long. Indian ocean. Lister, t. 548. f. 3. hetero- * 14. Taper, spiral, with three elevated ribs on the up- 36. Brown, roundish, striated. Indian ocean, adher. остеа. stropha. per side, and the wbirls reversed. Devonshire. Mon- ing to corals. Martini, i. t. 1. 9. tagu. 37. Smootb, white, the broader part straight, and probascicorrugata. * 15. Regular, spiral, transversely wrinkled, and um- transversely plaited'; 2 to 4 inches long. Martini, i. dea. bilicated. Devonsbire. t, 2. f. 18. A and B. lucida. * 16. Taper, spiral, very smooth and glossy; whirls 38. Polished, smoothish, with annulated plaits, a lit-protensa. reversed. Britain. Linn. Tr. v. t. 1. f. 31. tle tapering towards the end ; size of a quill. Indian vitrea. 17. Round, regular, spiral, orbicular, wrinkled, with and American seas. Martini, i. t. 2. f. 12. A. a thickened aperture. Greenland seas; shores of Bri- 39. Somewhat triangular, and a little flexuous, gigantea. tain. gradually tapering, violet; within smooth and pale contortu- * 18. Angular, rugged, and irregularly entwined; yellow; aperture white, with undulated striæ, and armplicata. transversely striated; 3 to 4 inches long. European ed with a conic tooth ; a foot high, and as thick as the and American seas, shores of Britain. Martini, i. t. little finger. Africa and America. Pallas, t. 10. f. 2 to 10. nebulosa, 19. Thick, wrinkled, and much twisted ; aperture * 40. Whirls 2, deeply and spirally grooved ; green-sulcuta. large and indented. America. Favanne, t. 6. f. 1. ish; minute. Coast of Pembrokeshire, on the roots of goreensis. 20. Round, cancellated, yellow, within borny; 8 to fucus digitalis. 9 inches long. Goree. Favanne, i. t. 6. f. 812. 41. Suboval, with 2 bends, imperforated; minute.ovalis. glomerata. 21. Round, glomerated, with decussated wrinkles. Found at Denbigh. European and Atlantic sea. Martini, i. t. 3. f. 23. 42. Regular, rounded; margin reflected at the aper-reflexa. lumbrica. 22. Round, flexuous, with a spiral, acute tip; trans- ture; minute. Pembrokeshire sands. lis. versely ribbed, and longitudinally wrinkled; 3 to 5 43. Regular, rounded, pellucid, with three whirls; cornea. 44. Semilunar, ventricose, white, opaque, glossy ; bicornis. conica. 23. Subcylindrical, flexuous ; spiral at the base. A. minute. Sandwich and Reculver. merica. Martini, i. t. 2. f. 15. * 45. White, opaque, glossy; semilunar and perfo-perforata. arenaria. 24. Jointed, entire, distinct, flattish beneath. India rated ; minute. Sandwich, Rare. and Africa. Martini, i. t. 3. f. 19. A, B, and C. 46. Oval, thin, smooth, pellucid, with milky veins ; lactca. afra. 25. Substriated, yellowish brown, round, twisted in minute. Sandwich. Very rares 1. f. a 举 gigantea. 1. Taper, subcylindrical, nearly straight, thick, and pellucid, with two internal tubes at the summit. Inhabits the sandy shores of Ceram, one of the Molucca islands, in shallow water. Rumphius, t. 41. f. D and E. This species grows to an immense size; and has been found no less than 5 feet 4 inches long, and the circumference at the base 9 inches, tapering upwards to 2 inches; the colour on the outside is milk-white; the inner surface rather of a yellow tinge. navalis. 2. Ship-worm; shell thin, cylindrical, smooth; more or less twisted; rather obtuse at the tip; 4 to 6 inches long. Britain. Don. t. 145. oak which were examined in the dock-yard of Ply. It has been observed that the teredo navalis cuts a- 3. Solid, cylindrical, undulated; 7 inches long. In utriculus. wood. Kemmener, t. I. 4. Clavated at one end, incurved at the other; nar-clava. rower, obtuse and perforated in the middle; 2 inches long. Found in the seed-vessels of the xylosteum granatum. Coromandel. Ency. Meth. t. 167. f. 6 to 16. Gen. 36. SABELLA, Sand Shell. mouth, and two thicker tentacula behind the head: SPECIES. At the smaller end the shell becomes thick and It is found in the sides and bottom of ships, and even the strongest oak, which has been some time under water. This testaceous animal was originally a native of the warmer climates, and was brought to Europe, where it has been produced, and has proved extremely destructive to the bottoms of ships, and to works constructed of wood, which remain for some time constantly under water. It appears, from some piles of solid 64 Sabella. 1. Solitary, loose, curved, with lentiform, glossy gra- scruposa. nulations; thickness of a swan's quill. India and American islands. 2. Solitary, fixed by the base, simple, curved, with scabra. radiated, rough granulations. America. Act. Petrop. 1766. t. 9. f. 1 and 2. * 3. Numerous, parallel tubes, communicating by an alveolata. aperture, forming in the mass the appearance of honey combs; 2 to 3 inches long. European coasts, Britain. Ellis Corals, t. 36. 4. Solitary, subcylindrical, papyraceous, chiefly com-chrysodon. posed of fragments of shells, thickness of a quill; 2 to 6 inches long. European and Indian seas, shores of Britain. Martini, i. t. 4. f. 29. and 30. * 5. Straight, conic, composed of minute particles of belgica. sand; 2 to 3 inches long. European coasts, shores of Britain. Martini, i. t. 4, f. 37. 6. Brown, with alternate white and black rings; rectangustraight, with a rectangular gibbous extremity; 9 inches la. long. Martini, i. t. 4. f. 31. 7. Cylindrical, conic, open at both ends; membra- capensis. naceous; rough, with interrupted, transverse striæ. Cape of Good Hope. Mull. Linn. Naturf. 6. t. 19. f. 6 and 7. 8. Cylindrical, black, smoothish on the outside; nigra. composed a a ammo * composed of minute particles of sand; inch long body prickly, jointed. Deeps of the Greenland seas ; Rivulets of Thuringia. Schroeter, t. 11. f. 1. fixed to stones. Fabr. fn. Groenl. p. 374. N° 369. stagnalis. 9. Straight, tapering, open at both ends ; smooth, 25. Cylindrical, composed of capillary, subcylindri- indica. * 26. Extremely fragile, cylindrical, composed of pure arenaria. conica. 10. Narrow, conic, smooth, straight, cinereous ; sand, slightly cemented together, without any internal with a blackish open tip, composed of very minute par- membrane; size of a raven's quill , from 1 to 2 inches ticles of sand ; not inch long. Schroeter, t. 11. f. 14. long. Dorsetshire coast. Montagu. uncinata. 11. Smooth, round, tapering, with an open hooked 27. Long, subcylindric, slender, fragile, composed of subcylin. tip; } inch long. Rivers of Thuringia. Schroeter, t. fine sand, and minute bits of broken shells, cemented drica. 11. f. D. f. 8. together on a fine membrane; 3 inches long. Salcomb sabulosa. 12. Cylindrical, closed at the tip, subclavated, per- bay. Montagu. forated, and composed of larger grains of sand; not an 28. Long, slender, gradually tapering to the lower letiformis. flat bits of stones, cemented together at their edges : 3 vegetabilis 13. Depressed, composed of fragments of twigs, to 4 inches long. Salcomb bay.- Some have been ob stems, and bark, and broken pieces of the tellina cor- served with a lateral branch near the smaller end, which 29. Small, short, composed of sand and minute bits curta. 14. Polygono-cylindrical, within smooth, composed of flat stones, agglutinated to a tough membrane ; size niaia. of fragments of cornu ammonis. Rivers. Schroeter, of a crow quill; an inch long. Inlet near Kings. t. 11. f. 10. bridge. This sabella is gregarious, covering the whole helicina. 15. Round, within smooth, composed of fragments of surface of the shore, appearing like bits of straw co the helix pusilla; an inch long. Stagnant waters of vered with mud. Montagu, 11 30. Short, broad, and very flat, composed of large compressa dimidiata. 16. One part of the shell composed of sand or gra. fragments of flat, bivalve shells, placed Frith the con vel, the other thicker, clavated, and composed of frag- cave side inwards; 1; inch long. Deeps at Torcross, The animals included under the preceding genus, fixa. 17. Composed of small stones ; tapering towards the have for their coverings particles of sand agglutinated tip; an inch long; affixed to stones in the water, and on the external membrane, and resemble rather the The latter form their calcareous integuments entirely clarata. 18. Composed of small stones; the open end clavat- from the secretions of their own surfaces, and are at. ; them essential and indispensable parts of their struccorticalis. 19. Composed of pieces of bark, towards the end of ture. The coverings of the sabellæ seem to be more of broken stems. Schroeter, t. 11. f. 5. an adventitious nature, and may be considered rather arundina. 20. Subconic, open at both ends, composed of frag- as serving the purposes of habitations, than as being cea. ments of the bark of reeds, placed on each other; an organized integrals of the contained animal. This geinch long. Schroeter, t. 11. f. 6. nus, therefore, does not come under the class of testa. aculeata. 21. Composed of small twigs, the points of wbich ceous animals; and indeed is by all physiologists of mo project a little ; an inch long. Thuringia, Britain. · dern times rejected from the arrangement of testaceous 65 marsupia. 22. Black; open end cylindrical and narrower, the Number of species included under each order, in the Enumeralis. other part tinged and ovate; 2 inches long. Schroeter, preceding classification. tion of the 2. t. 6. f. 21. MULTIVALVES species. 99 norwegica 23. Roundish, open at both ends, brittle, membrana BIVALVES ceous ; composed of very minute grains of sand; 4 UNIVALVES 1655 inches long. Norway. Schroeter, 2. p. 591. N° 20. lumbrica- 24. Coarse, creeping, fragile, open at both ends ; Total number of species 2409 tis. the animal not furnished with tentacula at the mouth ; exclusive of the sabellæ. * 655 CHAP. V. OF THE CONSTITUENT PARTS OF SHELLS, &c. HAVING in the former chapter enumerated, under the animal, and how it is enlarged as the animal ineach genus, all the species of testaceous animals which creases in size. These topics shall be the subject of the have been hitherto discovered ; and having given the present chapter, which may be conveniently divided characteristic marks by which each is distinguished, into the following sections. 1. Of the constituent parts which marks are derived from the shell or testaceous of shells. 2. Of their formation. 3. Of the colours of covering; we now propose to inquire what is the na- shells. 4. of the formation of the umbilicus and proture of this substance; in what way it is produced by tuberances, &c. 5. Of the pearl. SECT. |