Lew and Little Known American Paleozoic Ostracoda. Ill 
carapace a decided resemblance to Primitta. Two long and deli- 
cate spines, one in the antero-dorsal fourth, the other near the ven- 
tral edge, a little in front of the center, suggest the specific name. 
Size: Length, 0.91 mm.; height, 0.52 mm. Other specimens 
are one-third larger. 
When typical, this species resembles certain forms of Primitia 
and Leyrichiella very greatly, but specimens in which the anterior 
sulcus is faintly developed are not uncommon. These, then, are 
very much like the young of C. alata, which species I regard as 
closely related. Indeed, I would not be surprised should a more 
complete series than is now in my collection show them to be but 
varieties of one and the same species. 
Position and locality: Associated with C. a/afa in the lower 
shales of the Cincinnati Group, at Cincinnati, Ohio. 
CTENOBOLBINA TUMIDA, N. sp. 
Plate VIT, Figs. 5a, 56. 
Carapace sub-oblong, erect, dorsal edge straight, three-fourths 
as long as the valves ; ends subequal, the anterior often a little the 
narrowest, almost uniformly curving into the less convex, ventral 
edge. A narrow crenulated flange around the free margins. Pos- 
terior half of valves taken up by the remarkably tumid or sub- 
globular posterior lobe. In front of this a strong depression cut 
off below by a narrow low ridge, the postero-ventral prolongation of 
the anterior lobe. Inthe depression between this ridge and lobe 
and the much more prominent posterior lobe, a small, narrow ver- 
tical lobe. Surface sloping rapidly down to the free margins. The 
test is not very well preserved on any of the numerous valves 
before me, but the best present evidence of ele cons asviny'C. 
ciliata and other species of the genus. 
Size: Length, 1.15 mm.; height, 0.7 mm.; greatest convexity 
of posterior half of single valve, 0.38 mm.; thickness of anterior 
half of same, 0.28 mm. 
In the isolation of the small mesial lobe, this species approaches 
Beyrichia, but the posterior lobe is so decidedly ‘‘bulbous’’ that 
the generic reference can scarcely be questioned. The point 
referred to will at once distinguish the species from C. cé/éata, its 
nearest known relative. 
