Late Cenozoic Ostracodes — Holden 
27 
0.1 mm 
Fig. 18. Jugosocythereis venulosus n. sp. a-b, Holotype usnm 648765 ; a, lateral right valve view 
of carapace showing overlap of left valve; b, dorsal view, c, Paratype sdnh 1047; internal view of poorly 
preserved right valve; adductor scars in white. 
distribution: As fossils from T-ll (1 en- 
tire) and T-12 (5 valves; 3 entire). 
discussion: This species represents an ex- 
treme form of ornamentation for Jugosocy- 
thereis. The surface is finely reticulate and 
practically without the characteristic small 
ridges. Also, the subcentral swelling, alae, and 
posterodorsal complex are extremely tuberculate 
and localized. Sexual dimorphism in the species 
is not apparent. The species is named for its 
veinlike ornamentation. 
Genus Quadracythere Homibrook, 1952 
Quar dr acy there hornibrooki n. sp. 
Figs. 19 a-e 
diagnosis: Smooth median bar; trilobed pos- 
terior tooth; smooth anterior margin; divided 
adductor muscle scar pattern. 
description: Carapace stout, inflated, sub- 
quadrate. In lateral view: slightly concave dorsal 
margin symmetric with convex ventral margin; 
posterior margin concave in upper part, forming 
low caudal process in lower part; poorly devel- 
