FAUNA OF CHEMUNG BEDS AT HIGH POINT. Overlying the thick bedded "sandstone with vertical fucoids,” which was described by Mr. Hall as composing the terminal mass of the Portage sandstones, is a stratum 5 feet in thickness which contains a fauna of much interest. This was discovered in 1878 by Mr. D. D. Luther, on the summit of "High Point," a mountain standing 1,900 feet above the sea, and situated about 3 miles northwest of the village of Naples. The exposure of the stratum is quite limited, and, as it is in situ only on the sheer face of a high cliff, has been studied mostly from the fragments which have fallen into the talus below. I know as yet of no other outcrop of the stratum, although I have reason to believe that it will be found among the high hills lying to the south. The containing rock is a sandy limestone, or a sandstone, with a large intermixture of calcic carbonate brought in by the fossils it contains, and is in places largely composed of fragments of crinoid columns. It has afforded me the following fauna: Rhynchonella pugnus Martin. A. reticularis Linnæus. A. hystrix Hall. Streptorhynchus Chemungensis Hall. S. subattenuata Hall. S. mesacostalis Hall. S. bimesialis Hall. Ambocalia umbonata Conrad. Strophodonta Cayuta Hall. S. variabilis Calvin. S. exilis Calvin. Productella speciosa Hall. Orthis infera Calvin. Chonetes setigera Hall. Crania sp. Pterinea sp. Polypora sp. Fenestella sp. Zaphrentis sp. Receptaculites sp. Dadoxylon Clarkei Dawson. Rhynchodus sp. Cladodus sp., and other undetermined fish remains. In the summer of 1882 I made Dr. H. S. Williams, of Ithaca, acquainted with the locality, and he has identified the following additional species: 51 Productella dissimilis Hall. Orthis Towensis Hall. Strophodonta arcuata Hall. S. (Strophonella) reversa Hall. Stenochisma contractum Hall. Fistulipora occidens Hall and Whitfield. Of this fauna only the following species had been previously recognized from the Chemung group of New York State: Atrypa aspera Hall. A. reticularis Linnæus. A. hystrix Hall. Streptorhynchus Chemungensis Hall. Strophodonta Cayuta Hall. Spirifera mesacostalis Hall. S. disjuncta Sowerby. Productellà speciosa Hall. Chonetes setigera Hall. Ambocalia umbonata Conrad. Stenochisma contractum Hall. Rhynchonellæ very closely allied to pugnus Mart. have already been recognized in America by Meek 52 in the subcarboniferous rocks of Rockford, Indiana, and Chouteau Springs, Missouri, in forms which are closely comparable to the English and Irish carboniferous forms. These have been referred to the species R. Missouriensis Shumard.53 Marcou, in 1858, and McChesney, in 1860, described species of quite the same type as R. pugnus, the former under the name R. Rockymontana, the latter with the name R. eatoniaeformis, from the carboniferous of Utah and Illinois respectively. Although R. pugnus belongs to a carboniferous type, and occurs abundantly in the English and Irish carboniferous rocks, it is also in the same countries a member of the fauna of the Middle Devonian.54 It isa well-known fossil in the Rhenish Devonian 55 throughout 51 Am. Jour. Sci., Vol. XXV, Feb., 1883. Dr. Williams has somewhat forestalled my work upon this fauna by the publication of this article upon A remarkable Fauna at the base of the Chemung Group in New York, but my observations here indorse and materially strengthen the essential views there set forth. 52 Geol. Survey of Illinois, 1866, Vol. II, p. 154. 53 Geol. of Missouri, 2d Aun. Rep. 1855, p. 204, and Meek, Geol. Survey of Illinois, Vol. II, p. 153. 54 Davidson, Mon. British Dev. Brach., p. 60. 65 Maurer, Neues Jahrbuch, 1875; Kayser, Zeitschr. d. d. Geol. Gesell., Band XXIII. 56 the Stringocephalen Kalk and the Upper Calceola Schichten, but here it is not to be regarded as a diagnostic fossil, inasmuch as its more usual occurrence is at a higher horizon. Kayser, Roemer, and Schlönbach quote it from the vicinity of Eschweiler and Aachen, where it is associated with Spirifera disjuncta at a 'horizon which parallellizes with the Lower Chemung of America. In Belgium and the north of France it is quoted by Bureau" from the Cop Choux limestone, associated with Rhynchonella cuboides, and by Gosselet from the "Schistes de Famenne," in association with S. disjuncta and R. cuboides, both of which horizons agree, as nearly as we can expect agreement in so widely separated formations, with the Chemung group of New York. 58 The forms of this species occurring in the Rhenish and Harz Devonian show a variation from the typical forms of R. pugnus figured by Davidson, and this author has referred the examples figured by the brothers Sandberger to R. acuminata Martin. Nowhere, to my knowl edge, does this species in any one Devonian fauna present so considerable a variation as the specimens from High Point. Certain individuals with only a medium elevation of the mesial fold and with lateral plications acute at the margin, becoming obsolete over the visceral regions, represent the type of R. pugnus. Others, with extremely acute and elevated anterior margin and only traces of one or two lateral plications, represent the varieties of R. acuminata, mesogonia, or plicata Phill. R. pugnus is one of several Devonian species of cosmopolitan range, and it has from the time of its first appearance in the Middle Devonian of Germany to its disappearance in the Lower Carboniferous, adapted itself to the change in the probable westward migration of the Devonian fauna of Europe, and has as a specific type outlived, without much variation, most of its earlier associates. 59 Dr. Williams has compared the fauna represented in the second of the lists given above with a peculiar and interesting fauna originally described by Hall 60 from Lime Creek, near Rockford, Iowa, and subsequently reviewed by Dr. C. A. White.61 By these two authors this fauna was regarded as belonging to the Hamilton group. Later Messrs. Hall and Whitfield 62 published a study of the same fauna, describing some additional species, and referred it to the Chemung group, and more lately Mr. S. Calvin 63 has reviewed the fauna and given a complete list of its members as known to date. Calvin had also previously described 4 56 Kayser, Zeitschr, d. d. Geol. Gesell, Band XXII, p. 841. 57 Bull. Soc. Geol. de France, 2me ser., T. XVII. 58 Bull. Soc. Geol. de France, 2me ser., T. XVIII, p. 18. 59 Mon. British Dev. Brach., Pl. XIII. 60 Geology of Iowa, Vol. I, Pt. II, 1858. 61 Geology of Iowa, Vol. I, p. 187, 1870. 62 Twenty-third Ann. Rep. N. Y. State Cab. Nat. Hist., 1873. 63 Am. Jour. Sci., Vol. XXV, June, 1883. 64 Bull. U. S. Geol. Survey, Vol. IV, No. 3, 1878. an interesting fauna from a bed of black shales at Independence, Iowa, which underlies the main beds of the Devonian strata in that State, known as the Devonian limestones. The Rockford shales, containing the Lime Creek fauna, overlie these Devonian limestones, and several of the species occurring in the higher horizon are also found in these lower Independence shales. For the purpose of bringing out clearly the correspondence between the High Point fauna of Ontario County, and the fauna of the Lime Creek and Independence beds as given by Calvin, leaving aside the Colenterate fauna of the Lime Creek beds, the following table will suffice: Naticopsis gigantea H. and Whitfield Paracyclas Sabini White.. Cryptonella Calvini H. and Whitf Terebratula navicella H Gypidula occidentalis H. Gyp. munda Calvin.... Leiorhynchus Iris H Stenoschisma contractum, var. saxatile HI Rynchonella ambigua Calvin... R. pugnus Martin Atrypa reticularis Linnæus Atrypa hystrix H Atrypa a pera H. Cyrtina Hamiltoniæ, var. recta Spirifera Mac Bridei Calvin ... S. cyrtinaeformis H. and Whitf. S. subumbona H S. Orestes H. and Whitf S. Hungerfordi H. S. disjuncta Sowerby S. mesacostalis H 8. bimesialis H S. subattenuata H Ambocoelia umbonata Con Productella truncata II P. dissimilis H P. speciosa H Chonetes setigera H. Orthis impressa, var. Iowensis H Streptorhynchus Chemungensis Con Strophonella hybrida H. and Whitf.. Strophodonta exilis Calvin S. variabilis Calvin S. Canace H. and Whitf S. arcuata H S. Cayuta H Crania famelica H. and Whitf Fistulipora occidens II. and W Dadoxylon Clarkei Dawson. This fauna in Ontario County consists of twenty-six described species, indisputably of the age of the Chemung Period, as it contains eleven. species previously recognized from the Chemung group of New York, and lies 600 feet above the last stratum knowu to contain fossils of the Naples shales. But it embraces a large intermixture of species that are totally unlike those of the Chemung of New York, and which find their counterpart only at a distance of nearly 1,000 miles to the west. Fourteen species are common to the High Point strata and the Lime Creek beds overlying the Devonian limestones. Of twelve species occurring in the Independence shales, which underlie these Devonian limestones, nine occur also on High Point. Two species of the intervening Devonian limestones, viz., Spirifer bimesialis H., and S. subattenuata H., occur likewise at High Point. With the occurrence of these Chemung fossils abundantly at the base at the top of the Devonian series in Iowa, it becomes difficult to assign any definite horizon to the members of that series which will give them a correspondence with series in New York. The character of the fauna of the Independence shales leads us to the belief that the first Devonian fauna to appear in Iowa included an important representation from the Chemung fauna of New York in its probable migration westward from New York, to be succeeded in the limestones and shales above by a mingling of the Middle and Lower Devonian faunas of the east, and again by a return of the Chemung fauna with a more perfect development at the time of the deposition of the Lime Creek beds. That is, in the matter of relative age, all of these Iowa Devonian beds must be later in time of deposition than the Devonian of New York lying below the horizon of the High Point strata, and the age which saw the deposition of the Chemung sediments in New York was probably well toward its close at the time of the inception of the conditions in Iowa necessary for the deposition of the Independence shales. |