490 



LAMELLIBRANCHIA TA. 



[mod. 



the beaks; anterior end rounded; 

 beaks large, obtuse, and extending be- 

 yond the hinge-line; umbones large; 

 surface marked with concentric lines 

 of growth, and with strong transverse 

 lines over the umbonal region, some 

 of which extend nearly to the basal 

 line, the anterior ones curve a little 

 forward in passing over the umbones. 

 Collected by the author in the Hud. 

 Riv. Gr. at Versailles, Indiana. 



carinata, Hall, 1847, Pal. N. Y., vol. 1, p. 

 160, Trenton Gr. 



carrollensis, Worthen, 1882, Bull. No. 1, 

 111. St. Mus. Nat. Hist., Galena Gr. Pro- 

 posed instead of M. subnasuta of Meek 

 & Worthen, 1870, Proc.Acad. Nat. Sci., 

 p. 41, which was preoccupied. 



cincinnatiensis, Hall & Whitfield, 1875, 

 Ohio Pal., vol. 2, p. 88, Utica Slate. 



Fig. 851.— Modiolopsi8 oapcuc. 



concentrica, Hall & Whitfield, 1872, Ohio 



Pal., vol. 2, p. 86, Hud. Riv. Gr. 

 curta, Hall, 1847, Pal. N. Y., vol. 1, p. 297, 



Hud. Riv. Gr. 

 dicteus, Hall, 1867, 20th Rep. N. Y. Mus. 



Nat. Hist, p. 385, Niagara Gr. 

 (?) dubia, Hall, 1859, Pal. N. Y., vol. 3, p. 



264, Low. Held. Gr. 

 exilis. Billings, 1874, Pal. Foss., vol. 2, p. 



132, Up. Sil. 

 faba, Emmons, 1842, Geo. Rep. 2d Dist. 

 N. Y., p. 395, and Pal. N. Y., vol. 1, p. 

 158, Black Riv., Trenton, and Hud. 

 Riv. Grs. 



faberi, n. sp. 

 Shell elon- 

 gate, nearly 

 twice as long 

 as high ; be- 

 low the aver- 

 age size of 

 species in 

 this genus ; 

 broadest be- 

 hind the middle, and much contracted 

 in front of the beaks ; hinge-line nearly 

 straight from the anterior end to the 

 middle ; it then becomes arcuate to near 

 the posterior end, which is abruptly 

 rounded ; basal line slightly sinuate at 

 the anterior third from the cincture, di- 

 rected downward and backward from 

 the anterior part of the umbo ; beaks 



Fig. 852.— Modiolopsis faberi. 

 L,eft valve. 



strong, projecting anteriorly beyond the 

 hinge-line; umbones high, subangular, 

 and gradu- 

 ally declin- 

 ing toward 

 the postero- 

 basal line ; 

 anterior 

 m uscular 



impression Fig. 853.— Modiolopsis faberi. 

 vwv lorwp Cardinal view, showing 

 \viy Jdige, greateat thickness of shell 

 Circular, toward the posterior, 

 deep, and 



situate at the anterior end, in front of 

 and below the beaks; dorsal ligament 

 very large. Distinguished from M. con- 

 centrica in its general outline, more 

 elongate form, more prominent beaks, 

 and higher and more angular umbones. 

 Hud. Riv. Gr., at Cincinnati, 0. The 

 specimen figured is from 

 the collection of Charles 

 Faber. 

 gesneri, Billings, 1862, Pal. 

 Foss , vol. 1, p. 43, Tren- 

 ton and Black Riv. (Jrs. 

 latus, see Cypricardites 



latus. 

 maia, Billings, 1862, Pal. 

 Foss., vol. 1, p. 44, Tren- 

 ton Gr. 

 meyeri, Billings, 1862, Pal. 

 Foss., vol. 1, p. 42, Tren- 

 ton Gr. 

 modiolaris, Conrad, 1838, 

 (Pterinea modiolaris,) 

 Ann. Geo. Rep. N. Y., p. 118, and 

 Pal. N. Y., vol. 1, p. 294, Hud. Riv. Gr. 

 modioliformis, Meek & Worthen, 1868, 

 Geo. Sur. 111., vol. 3, p. 294, Tren- 

 ton Gr. 

 mytiloides, Hall, 1847, Pal. N. Y., vol. 1, 



p. 157, Black Riv. and Trenton Grs. 

 nais, Billings, 1862, Pal. Foss., vol. 1, p. 

 45, Black Riv. Gr. 



Fig. 854.— Modiolopsis modiolaris. Hinge and 

 pallial line and muscular impression. 



nasuta, Conrad, 1841, (Cypricardites na- 



sutus,) Ann. Rep. N. Y., p. 52, and Pal. 



N. Y., vol. 1, p. 159, Trenton and Hud. 



Riv. Grs. 

 nuculiformis, see Tellinomya nuculiformis. 

 obtnsa. Hall, 1847, (Modi'ola obtusa,) Pal. 

 . N. Y., vol. 1, p. 40, Birdseye Gr. 

 occidens, Walcott, 1885, Monogr. U. S. 



Geo. Sur., vol. 8, p. 77, Trenton Gr. 



