414 Beecher and Clarke — Lower Oriskany Fauna, etc. 



70. Cyrtina rostrata, Hall. 71. G. cf. Dalmani, Hall, of the Shaly limestone 



7 2. Meristellasp.il. This shell has many points of similarity with M. oblata 

 of the Oriskany. It is, however, a smaller, much more strongly trihedral shell, 

 with the aspect of a gigantic M. lenta. 73. Meristella cf. laevis of the Lower 

 Belderberg. 74. Meristella sp. n ? A large oon-sinuate species. 



(H) 75. Trematospira mult {striata, Hall, of the Shaly limestone. 



(D) 76. Gozlospira sp. n. In size this shell resembles G. Camilla, of the Cornif- 

 erous limestone, while it bears the external ornament of G. concava of. the Shaly 

 limestone, though the plications are rather more numerous. 



(H) 77. Ccelospira sp. of the small size of G. concava but more regularly plicate. 



78. Lepcocoelia flabellites, Hall. (D) 79. L. acutiplicata, Hall, of the Cornifer- 

 ous limestone. 



(H) 80. Anastrophia sp. n. A very finely plicate species. 



81. Rensselasria ovoides, Eaton. 82. R. Suessiana, Hall ? 83. R. ovalis, Hall? 



84. Rhynchonella oblata, Hall. 85. R. Barrandii, Hall. 86. R. cf. speciosa, 

 Hall. 87. R. sp. ? 



(H) 88. Eatonia medialis, Hall, of the Shaly limestone. 89. E. peculiaria, 

 Conrad. 



(D) 90. Gentronella, sp. n. of the type of 0. glans-fagea, but of great size. 



(H) 91. Cryptonella sp. n. Similar to an undescribed species in the Shaly 

 limestone. 



Eryozoans. (D) 92. Fenestella celsipora, Hall, of the Corniferous limestone. 



93. F. sp? 



(D) 94. Hemitrypa cf. columellata, Hall, of the Corniferous limestone. 



95. Polypora sp ? 96. Reptaria sp. 97. Hederella sp. 98. Clonopora sp. 

 99. Fistulipora sp. 



Corals. (H) 100. Zaphrentis cf. Rozmeri of the Shaly limestone. 101. Z sp. ? 

 102. Romingeria sp. 103. Monticulipora, a branching species. 104. Trachy- 

 pora, sp. 



Crinoids. 105. Edriocrinus sacculus, Hall. 



Sponges. 106. Hindia sp. 



This remarkable association of species furnishes the missing 

 link in the evolution of the Lower Helderberg into the typical 

 Lower Devonian fauna. While the presence of so many posi- 

 tive Oriskany types determines the fauna! quantivalence, the 

 perdurance of species and modifications of specific expressions 

 characteristic of the Shaly limestone fauna, and the inception 

 of upper Lower Devonian specific forms, render this combi- 

 nation altogether unusual and of prime significance in the cor- 

 relation of our earlier Devonian. The southwestern extension 

 of the Oriskany (Hipparionyx) fauna, as in Maryland, is com- 

 plicated with the Lower Helderberg, but to a less degree than 

 here; while in the representative of the same fauna in the 

 Province of Ontario there is a great predominance of Upper 

 Helderberg species. With the 46 species which have been 

 identified in the Hipparionyx fauna of New York (see list 

 published by Mr. Charles Schuchert, in Eighth Annual Report 

 of the New York State Geologist, p. 50, 1889), the 106 or 

 more species of the Becraft's Mt. fauna are in striking contrast, 

 and no element so strongly enforces this contrast or is so 

 unique in itself as the crustacean. The association is indu- 

 bitably of early Oriskany age and is eminently the Trilnbite or 

 Dalmanites facies of the Oriskany fauna. J. M. c. 



