KNOWN SPECIES OF MARINE OSTRACODA. 369 



set rounded pits of irregular size. In the intervals between the hollows, especially near 

 the ventral border, small tubercles are situated. These, however, are few in number 

 compared with the pits. 



Length 4^ in. ('63 ram.). 



Hob. Hunde Islands, 28-40 fathoms {Dr. Sutherland's dredgings). One valve. 



The shell-sculpture of this species agrees very much with that of Cy there kostelensis 

 as described by Dr. Egger ; but in other respects it seems to be perfectly distinct. 



8. Cytherideis tigrina, n. sp. (PI. LVIII. fig. 5, a-d.) 



Valves oval, convex ; extremities rounded, nearly equal. Anterior margin forming a 

 wide flattened lamina. Dorsum arched. Ventral margin slightly convex, sinuate at its 

 anterior third. Seen from above, the carapace is ovate, pointed in front, well rounded 

 behind. Surface smooth, white or light grey, marked with bands or patches of brown, 

 and bearing a few scattered papillae. 



Length -^ in. ('5 mm.). 



Hah. Australia (littoral shell-sand, Melbourne). Many specimens. 



Genus Cytheridea, Bosquet. 

 Animal a Cythere. Carapace subtriangular or triangularly ovate, highest usually be- 

 neath the anterior hinge. Surface smooth, papillose, or pitted, occasionally reticulated. 

 Hinge-margin of the right valve marked by a series of small tubercles, which are 

 received into corresponding depressions of the opposite (left) valve. These tubercles or 

 crenulations are mostly disposed in two terminal groups (see PI. LVIII. fig. II d, 

 fig. 13 d), and the intervening portion of the valve-margin is plain or may be marked 

 by minute tubercles on the left and corresponding fossse on the right valve. Ventral 

 margin somewhat incurved. Lucid spots arranged in a transverse row near the centre 

 of the valve ; mostly one or two detached spots in front of the main group. 



1. Cytheridea kirkbii, n. sp. (PI. LVIII. tig. 14, a-c.) 



Valves oblong, oval or subtetragonal, not twice as long as broad, scarcely at all 

 narrowed posteriorly. The ventral margin is nearly straight, with a slight median con- 

 vexity. The anterior, posterior, and dorsal margins are all arched and somewhat 

 flattened. The anterior and posterior borders are often armed on their lower portions 

 with a series of blunt teeth, about eight in number at each end ; but very frequently one 

 or both extremities are destitute of these. Dorsal aspect oblong-oval. Surface quite 

 smooth or marked with faint, shallow, and distant pittings, bearing also a few scattered 

 hairs. Lucid spots large, angular, arranged irregularly a little in front of the centre of 

 the valve. 



Length yo in. ('84 mm.). 



Hab. Honduras (calcareous sand, shallow water). Many specimens. 

 VOL. V. PART V. 3 c 



