KNOWN SPECIES OF MARINE OSTRACODA. 379 



marked with longitudinal rows of punctations, coalescing on the ventral surface into 

 grooves or striae. End view cordate. 



Length ^ in. ('54 mm.), 



Hab. Levant (sponge-sand). 



17. Cythere PUMicosA, n. sp. (PI. LXL fig. 3, a-c.) 



Carapace oblong, convex, quadrilateral, considerably elevated, and marked more or 

 less distinctly with two sigmoid ridges and an intervening depression. Anterior 

 margin broad, somewhat flattened, with rounded angles ; posterior rounded, denti- 

 culate. Dorsal margin nearly straight ; ventral shghtly sinuated. Dorsal profile ovate. 

 Surface-sculpture consisting of angular excavations of irregular shape, but mostly 

 oblong and disposed in longitudinal series. 



Length ^ in. ('63 mm.). 



Hah. Turk's Island (shallow water). 



18. Cythere cribriformis, n. sp. (PI. LXI. fig. 6, a-d.) 



Subquadrangular, trapezoid, convex ; margins (except the ventral) strongly and irre- 

 gularly toothed. Extremities straight, with rounded angles, converging towards the 

 dorsum. Dorsal border straight ; ventral convex, emarginate, and nearly devoid of 

 spines. Dorsal aspect broadly ovate. Surface of the carapace covered with a strong, 

 elevated reticulation enclosing angular cells of irregular shape, the whole structure 

 being very similar in appearance to the calcareous plates of some of the sea-cucumbers. 



Length -^ in. ('74 mm.). 



Hab. Levant (sponge-sand). One specimen. 



19. Cythere normani, n. sp. (PI. LXI. fig. 5, a-d.) 



Carapace convex, trapezoid in outline. Dorsal and ventral margins slightly arched 

 outwards. Anterior margin beset, along its inferior half, with long, blunt teeth. 

 Posterior margin armed with two or three strong teeth and several smaller ones. 

 Dorsal aspect oval, with several projecting spines towards the extremities. Surface 

 covered with a network of sharply defined ribs, crossing each other nearly or quite at 

 right angles, but becoming less distinctly angular towards the edges of the valves. A 

 sharp keel, bearing posteriorly a single strong spine, runs along the lower border, and 

 mostly bifurcates on the ventral aspect, the upper branch being continued along the 

 posterior border of the valve to the dorsal margin, thus bounding the reticulated 

 portion of the shell. 



Length -^ in. ('78 mm.). 



Hab. Abrolhos Bank. Several specimens. 



The only described species which bears any close resemblance to the present is 

 C. arachnoidea. Bosquet. It differs from C. normani in outline, also in having a row of 



3 D 2 



