ANATTNID-S!. 153 



Ne^romya, Gabb, 18t2. 



Distr. — N. quadrata, Gabb (cviii, 78-80). Tertiary; West 

 Indies. 



Shell thin, translucent, in shape approaching Pholadomya, 

 ends closed ; hinge with a prominent tooth in the right valve, 

 articulating behind a smaller similar one in the left valve ; an 

 anterior and posterior lateral tooth in each valve ; mantle-margin 

 without sinus. 



This genus, in its thin character and minute hinge, is closely 

 allied to Pholadomya, Thetis, and Nesera, but differs from all in 

 the details of the hinge. Nesera has no cardinal tooth, but in 

 its place a cartilage-pit in each valve ; it has a single posterior 

 tooth, while this genus has the anterior equally well-developed. 

 In having corresponding teeth in both valves it differs from 

 Thetis, while its well-specialized hinge and its closed ends dis- 

 tinguish it from Pholadomya. 



OsTOMYA, Conrad, 1814. 



Distr. — 0. papyria, Conr. (cviii, 81, 82;. Tertiary; Upper 

 Amazon. 



Shell thin, concentrically plicate ; hinge with a spoon-shaped 

 oblique fosset in the left valve, and a small tooth near the apex ; 

 right valve cartilage-fosset ver}^ oblique, almost parallel with the 

 hinge-line. 



Tellinopsis, Hall, 1869. 



Syn. — Tellinites, M'Coy (part). 



Distr. — T. subemarginatfi, Conr. (cY\u,So\ Fossil. Hamilton 

 Group, New York. 



Shell thin, fragile, general form of Tellina, with moderately 

 convex valves, small subcentral beaks, having their apices 

 directed backwards with a shallow posterior furrow ; hinge 

 apparently edentulous ; ligament external, small ; muscular 

 impression very faint, situated near the cardinal extremity ; pal- 

 lia! line undetermined. 



Sanguinolites, M'Coy, 1844. 



Syn. — Cypricardites, Conr., 1841 (part). 



Distr. — Carbon.; Eur. S. dii<cors, M'Coy. 



Very elongated, with subparallel upper and lower margins, 

 rounded anteriorly, obliquely truncate posteriorly, with an 

 oblique prominent ridge from the beaks to the postero-inferior 

 margin, very inequilateral, beaks slightly prominent, close 

 together, subanterior ; anterior muscular impression oval, 

 distinct, with a small groove above it, and both posteriorly 

 bounded by a prominent ridge, posterior muscular scar faint; 

 cardinal margin internally thickened the whole length, probably 

 for the support of a ligament; surface concentrically (or 

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