OSTRACODA. 



507 



Another great group of the Ostracoda is that of the Cypridinidce, 

 in which the carapace is compact, smooth, or punctate, or striated, 

 with a deep incision in the anterior margin for the exit of the larger 



Fig. 361. — Types of Ostracoda. A, The test of Cyprisfaba, from the Miocene, viewed side- 

 ways, and enlarged fifteen times ; a', The same, viewed from the dorsal margin ; b, Isochilina 

 Ottawa, enlarged four times (left valve and ventral view)— Ordovician ; c, Leperditia Joseph- 

 ana, of the natural size (right valve and anterior view) — Ordovician ; d, Leperditia solitaria, 

 enlarged, showing the eye-spot and muscular impression — Silurian ; E, Priinitia sp. — Silui-ian ; 

 F, Primitia strangidata, Ordovician, enlarged ; G, Right and left valves of Prijnitia tarda — 

 Silurian ; h, Beyrichia complicata —Ordovician ; 1, Beyrichia (?) oculifera, showing the elevated 

 eye-spot, greatly enlarged— Ordovician ; J, Entomis tuberosa, Jones ( = E. pelagica, Barr.), right 

 valve, enlarged twice— Silurian ; K, Entomis impendens, enlarged— Silurian ; l, Cypridina 

 IVrightiana, left valve, enlarged four times — Carboniferous ; M, Dorsal view of a small example 

 of Entomoconchiis Scouleri, enlarged four times — Carboniferous ; n, Left valve of Polycope 

 simplex, enlarged eight times — Carboniferous; O, Cypris Browuiana, viewed dorsally, enlarged 

 twenty-five times — Pleistocene ; p, Candona Candida, viewed ventrally, and similarly enlarged 

 — Post-Tertiary and Recent ; Q, Cythere convexa, right valve, similarly enlarged— Pliocene and 

 Recent; r, Interior of left valve of the same. (After Barrande, Rupert Jones, M'Coy, Hall, 

 and G. S. Brady.) 



antennae. Numerous living forms of the Cypridinida are known, 

 and the family is represented in past time principally by the three 

 generic types, Cypridina, Entomis, and Entomoconchus, the last two 



