FOSSILS OF THE DEVONIAN. 



117 



Genus STKEPTOJRHYNCHUS King. 



Streptorhynchus Chemungensis Conrad (Sp.). 

 Plate xiii, figs. 7, 16. 



Strophomena Chemungensis Conrad, 1842. Jour. Acad. Nat. Sci. Philad., vol. viii, p. 



257. 



Ufurcata Hall, 1842. Geol. Eep. Fourth District New York, p. 266, fig. 2. 

 arctostriata Hall, 1842. Ibid., p. 266, fig. 3. 

 pectinacea Hall, 1842. Ibid., p. 266, fig. 4. 

 Orthis perversa Hall, 1857. Tenth Ann. Eep. N. Y. State Cab. Nat. Hist., p. 137. 



inequalis and 0. pravus Hall, 1858. Geol. Iowa, vol. i, pt. 2, p. 490. 

 Streptorhynchus Pandora Billings, 1860. Canadian Jour., vol. v, p. 266, and Geology 



of Canada, 1863, p. 369, fig. 384. 

 Orthisina arctostriata Hall, 1860. Thirteenth Ann. Kep. N. Y. State Cab. Nat. Hist., p. 80. 



alternata Hall, 1860. Ibid., p. 81. 



Streptorhynchus Chemungensis Hall, 1867. Pal. N. Y., vol. iv, p. 67, plates iv, ix, x. 

 var. A. Streptorhynchus pandora Billings, 

 var. B. 8. arctostriata Hall, 

 var. C. 8. perversa Hall. 



var. D. 8. pectinacea Hall, 1867. Pal. N. Y., vol. iv, pp. 68-73. 

 Pandora Nicholson, 1874. Pal. Prov. Ontario, p. 70. 



Hemipronites Chemungensis, var. arctostriata Meek, 1877. Geol. Expl. Fortieth Par., 

 vol. iv, p. 35, pi. iii, fig. 2. 



Three "quite distinctly marked varieties of this extremely variable spe- 

 cies were collected from the Devonian limestone of Lone Mountain and the 

 Eureka District. 



The first is that of the typical form of shell described by Conrad, 

 many illustrations of which are given by Professor Hall in volume four of 

 the Paleontology of New York (plate x, figs. 11-17). The Nevada form is 

 shown on our plate xiii, fig. 16. Another, and by far the most abundantly 

 represented variety, is var. Pandora (Pal. N. Y., vol. iv, pi. iv, figs. 11-19; 

 pi. ix, figs. 18-25, 27; and pi. x, fig. 1). 



In New York the species ranges from the Upper Helderberg up into the 

 Chemung Group, and in the Eureka District from the base to the summit of 

 the Devonian limestone. At The Gate, northwest of Eureka, the small 

 form characteristic of the Chemung Group of New York, also of the Cor- 

 niferous limestone of the Upper Helderberg, occurs in a dark limestone. 

 This is the exact locality from which the specimen mentioned by Mr. Meek 

 was obtained and referred by him to the variety arctostriata. The speci- 



