688 



BRACHIOPODA. 



[CRY. — I^EP. 



of the posterior impressions starts a 

 broad vascular sinus, strongly sinuous 

 near its point of departure, narrowing 

 gradually in following the contour of 

 the valve, emitting from its marginal 

 side dichotomizing secondary branches. 

 Type C. mrdiianenxi*, (Ehlert. It prob- 

 ably includes Crania hamHtonU , Hall. 

 and C. greenii, 8. A. Miller, 

 ulrichi, Hall, 1892, Pal. N. Y., vol. 8, 

 p. 181, Trenton Gr. 



Cryptoneu. \ ovalis, S. A. Miller, 1891, Ad- 

 vance Sheets 17th Rep. Geo. Sur. Ind., 

 p. 76, Ham. Gr. 

 traversensis, Winehell, 1866, (Terebratula 

 travel -inns, j Rep. Low. Renin. Mich., 

 p. 95. Hani. Gr. 



Dervya, Waagen, 1884, Palseontologiea ln- 

 dica, Ber. l.'!, vol. l, pp. 676, 591 to 

 607. [Kty. proper name.] This genus, 

 according to Hall, is distinguished from 

 tStreptorkjfnchui by the presence of a 

 median septum in the pedicel valve. 

 He notes m> other generic difference. 

 Type D, regularu, Waagen. Hall refera 

 to this genus ()rihi* heobuk, Hall, Orthit 

 robusta, HM, Hemipronita (Streptorftyn- 

 cfatf) cram**, Meek A ll.iyden, and re- 

 gards Be mif ron iU t lamttm$it and //. 

 richmondX McChesney, as synonyms for 

 11. era win. I consider Orlhis robutta, 

 Hall, more closely related to Hemipro- 

 niUt orantM, Meek, than either H.lasall- 

 entit or //. rii-iiiiiKinii, MoCheaney, and 

 if one is to be retained as a species all 

 three should be, and in no event is 

 either one of them congeneric with 

 Orihia heokuk. Hence. I see no propriety 

 in the use of the word Derbya as applied 

 to American fossils, and as I have seen 

 no typical specimens belonging to the 

 genus, I express no opinion as to its 

 value. Hall, however, describes Derbya 

 broadheadi, D. I>< miiili, J), ci/mhula, D. 

 affirm, and I), biloba, from the Up. Coal 

 Ideas,, Pal. N. Y., vol. 8, pp. 347 to 350, 

 and on p. 346 D. ruginosa, from the Ke- 

 okuk Gr., and D. costaiula from the 

 Kaskaskia Gr. All of these may be re- 

 ferred to Streptorhynchus, and it is not 

 too much to say that Meek would have 

 classed all of them as synonyms for 

 Streptorhynchu* cramun. 



Discina concordensis, Sardeson, 1892, Bull. 

 Minn. Acad. Nat. Sci., vol. 3, p. 328, 

 Trenton Gr. 

 keokuk, Gurley, 1884, New Carb. Foss., 



p. 6, Keoknk Gr. 

 sampsoni, 8. A. Miller, 1891, Advance 

 Sheets 17th Rep. Geo. Sur. Ind., p. 80, 

 Chouteau limestone. 



Discinopsis, Matthew, 1892, Pal. N. Y., vol. 

 8, p. 105. [Ety. from resemblance to 

 Discina.] Shell subcircular, depressed 

 conical ; apex ex centric ; apex of the 

 pedicel- valve truncated, with a circular 

 aperture ; interior having a pair of di- 

 verging furrows from the beak, that con- 



; verge toward the anterior margin, and 



inclose a thickened area, which, in the 

 subumhonal region, is apparently free 

 and projects like a shelf, from beneath 

 which the foramen probably opened ; 

 shell substance tenuous, apparently 

 corneous ; surface marked concentric- 

 ally, and also with radiating strise. Type 

 Aerotreta gulielmi, Matthew. 



Eatonia variabilis, Whiteaves, 1891, Cont. 

 to Can. Pal., vol. 1, p. 233, Devonian. 



HnUina, Winched A Schuchert, 1S92, Am. 

 Geo., vol, 9, p. 291. [Ety. proper name.] 

 Shells small, articulate, rostrate, bicon- 

 vex, semi plicate ; pedicel opening 

 bounded laterally by incomplete del- 

 tidial plates; calcined brachial sup- 

 ports long and much like Waldheimia. 

 Type //. taffordi. described at the same 



Siace with meoueUi, from Trenton Gr. 

 either one defined so as to be recog- 

 nized. 



Koninckma aniericana, Swallow, may be 

 stricken from the list as it is not a 

 Koninckina,' and is too poorly defined 

 to be recognized. 



Kitokoina lahradorica var. swantonensis, 

 Waleott. L889, 1'roc. .Nat. Mus., vol. 12, 

 p. 86, I 'p. Taoonic. 



Lept.ena charhilliv, Winched tt Schuchert, 

 1892, Am. Geo., vol. 9, p. 288, Trenton 

 Or., and l J lectambonitex gibboaw, from 

 Galena Gr. Not defined so as to be 

 recognized, 

 minnesotensis, Sardeson, 1892, Bull. Minn. 

 Acad. Nat. Sci , vol. 8, p. 329, Trenton 

 Gr., and prs&coais, recede i is and saxea, 

 I Ind. Riv. Gr. 



Lept.knisca, Beecher, 1890, Am. Jour. Sci. 

 and Arts. 8er. 3, vol. 40, p. 239. [Ety. 

 diminutive of Leptama.] Shell concavo- 

 convex, attached to foreign objects by 

 calcareous cementation of the ventral 

 beak; valves articulated by teeth and 

 sockets ; dorsal valve concave ; inte- 

 rior with broad spiral impression on 

 each side of the median line, making a 

 single volution; adductor impressions 

 small ; cardinal line narrow, bearing in 

 the center two prominent, bilobed, car- 

 dinal processes, separated to admit the 

 vertical septum in the opposite beak ; 

 ventral valve convex, area elongate, 

 triangular ; fissure covered with a ped- 

 icel sheath ; cardinal muscular scar sup- 

 f)orted on or limited by two elevated 

 amellee ; cavity of beak divided by a 

 vertical septum, on each side of which, 

 in the anterior half, is a small, adductor 

 scar ; shell structure punctate. Type 

 L. concava. 

 adnascens and L. tangens, Hall, 1892, Pal. 



N. Y., vol. 8, p. 352, Low. Held Gr. 

 concava, Hall, 1857, (Leptsena concava,) 

 10th Rep. N. Y. St. Nat. Hist., p. 47, 

 and Pal. N. Y., vol. 3, p. 197, Low. 

 Held. Gr. 

 Leptklla, Hall, 1892, Pal. N. Y., vol. 8, 

 p. 293. [Ety. leptos, thin.] Shell small, 

 concavo-convex, semicircular or semi- 



