664: CAMBEIAN BEACHIOPODA. 



Genus DISCINOLEPIS Waagen. 



[dltTKoc, quoit; and ker^ic, scale.] 



Disdnolepis Waagen, 1885, Mem. Geol. Survey India, Paleontologia Indica, 13th ser., Salt Range Fossils, vol. 1, 

 pt. 4, fas. 5, pp. 749-750. (Described and discussed as a new genus, part of the next to the last paragraph being 

 copied below.) 



Disdnolepis Waagen, Hall and Clarke, 1892, Eleventh Ann. Rept. State Geologist New York for 1891, p. 247. 

 (Described.) 



Disdnolepis Waagen, Hall and Clarke, 1892, Forty-fifth Ann. Rept. New York State Museum for 1891, p. 563. (Copy 

 of preceding reference.) 



Disdnolepis Waagen, Hall and Clarke, 1892, Nat. Hist. New York, Paleontology, vol. 8, pt. 1, p. 90. (Original 

 description, Waagen, 1885, p. 749, copied.) 



Disdnolepis Waagen, Walcott, 1908, Smithsonian Misc. Coll., vol. 53, No. 4, PL XI, and pp. 142 and 146. (Classi- 

 fication of genus.) 



As this genus is based on one species, the description of the latter will give all that is 

 known of the genus. Waagen [1885, p. 749] states that this genus diifers from all described 

 genera of the Discinidse: 



From Disdna, Disnnisca, and Orhiculoides it differs in having an incision and not a slitlike foramen in its lower 

 valve for the passage of a peduncle. In Trematis a similar incision or emargination seeras sometimes to occur, but 

 the sculpture of the valves is quite different from that appearing in Disdnolepis. Schizocrania has an incision, but 

 it is much larger than in the Indian form. 



Type. — Disdnolepis granulata Waagen. 



DisciNOLEPis GRANULATA Waagen. 

 Plate LXXXI, figures 3, 3a-b. 



Disdnolepis granulata Waagen, 1885, Mem. Geol. Survey India, Paleontologia Indica, 13th ser.. Salt Range Fossils, 



vol. 1, pt. 4, fas. 5, pp. 750-751, PL LXXXVI, figs. 5, 6, and 7. (Described and discussed as a new species. 



The specimen represented by fig. 6 is redrawn in this monograph, PL LXXXI, fig. 3; the specimen represented 



by fig. 5 is redrawn (in different positions) in this monograph, PL LXXXI, figs. 3a and 3b.) 

 Disdnolepis granulata Waagen, 1891, idem, vol. 4, pt. 2, PL II, figs. 15 and 16. (No text reference. Figs. 15 and 16 



are drawn from the specimens represented in the preceding reference, PL LXXXVI, figs. 5 and 6, respectively.) 

 Disdnolepis granulata Waagen, Hall and Clarke, 1892, Eleventh Ann. Rept. State Geologist New York for 1891 



p. 247, figs. 256 and 257. (No text reference. Figs. 256 and 257 are copied from Waagen, 1885, PL LXXXVI 



figs. 5b and 7, respectively.) 

 Disdnolepis granulata Waagen, Hall and Clarke, 1892, Forty-fifth Ann. Rept. New York State Museum for 1891 



p. 563, figs. 256 and 257. (Copy of preceding reference.) 

 Disdnolepis granulata Waagen, Hall and Clarke, 1892, Nat. Hist. New York, Paleontology, vol. 8, pt. 1, p. 90, figs 



45 and 46. (No text reference. Figs. 45 and 46 are copied from Waagen, 1885, PL LXXXVI, figs. 5b and 7 



respectively.) 



Shell transversely broad oval. Ventral valve nearly flat except at the umbo and apex. 

 Apex a httle in front of the posterior margin and about three-fourths of a millimeter high; it 

 is divided by a median depressed line which gives a slightly elevated semicircular node on each 

 side. From the depressed median line a narrow, elongate, triangular opening extends to the 

 margin of the valve; this opening has the position and form of the false deltidium of some 

 species of Acrotreta, but there is no outline of an area. The lines and striae of growth arch 

 around and terminate at the edges of the opening. 



Surface of the shell marked by fine concentric lines of growth and fine papillae which are out- 

 lined by oblique lines curving from each side of the shell forward and then outward to the 

 opposite side from which they originate. It is the same type of surface as that on Micromitra 

 CipTiidella) pannula (White) (PI. IV). Where the surface is slightly worn the papillae appear like 

 fine granules. 



The substance of the shell appears to be calcareocomeous and the shell to be made up of 

 several thin lamellae. The two ventral valves are 5 mm. in width and 4 and 5 mm. in length, 

 respectively. 



These measurements differ from Waagen's, but as the shells are imperfectly preserved at 

 margins the size assumed is a matter of personal judgment. 



