390 Prof. T. Rupert Jones—Fossil Ostracoda from U. States. 
Cluthe, Brady, Crosskey, and Robertson,’ which presents variable 
aspects, with its irregular mammillated surface and subquadrate 
carapace, is decidedly a nearer ally. 
In our specimen the valves are broad (high) in front, narrow and 
subtruncate behind, the dorsal and ventral borders sloping backwards, 
and the ventral region bears a definitely sharp ridge (not broad and 
rounded as in C. Cluthe) for two-thirds of its length. There is also 
a central tubercle on the valve, with a swelling in front and behind it. 
Differing in marked features from the other species, this may be 
designated Cythere monticula. 
From the Bear-River Formation; Cokeville, S.-W. Wyoming. 
VII. Cyrueripza, Bosquet. 
12. CyrHERIDEA TRUNCATA, sp. nov. Pl. XV. Figs. 4a, 6. 
Length -7, height -5, thickness ‘3 mm. 
There is no evidence of the Cypridean hook in this form, though 
it has some resemblance to a possibly truncate form of Cypridea 
punctata” (Forbes); but I prefer to associate it with Cytheridea. Its 
subtrigonal shape, with truncate front, and oblique posterior end, are 
characteristics. Its edge view is narrow-oval. 
On the surface is visible a shallow pitting, looking almost like 
a reticulation. 
From the Bear-River Formation; Cokeville, S.-W. Wyoming. 
13. CyTHERIDEA TENUIS, sp. nov. Pl. XV. Figs. Ta, 0. 
Length °6, height -25, thickness -2 mm. 
This is another form probably belonging to Cytheridea. The cast 
(like Fig. 4) has not retained (if it ever had) any evidence of the 
Cypridean beak-like process and its accompanying notch. It has a 
long subtriangularly ovate shape, like that of many different kinds 
of Ostracodes. The front is well rounded; the posterior rounded, 
but narrow ; the ventral border is straight; the dorsal elliptical, 
and most convex at the anterior hinge, as in many of the Cytheride. 
The surface shows some slight tuberculation. 
From the Bear-River Formation ; Cokeville, 8.-W. Wyoming. 
VIII. Cyrumripets, Jones, 1857; and Brady and Norman, 1889. 
14. CyTHERIDEIS HQUALIS, sp. nov. Pl. XY. Figs. 11a, 6. 
Length 6, height -25, thickness -4 mm. 
It is difficult (if not impossible) to place this form among fresh- 
water and brackish Ostracoda. The Cypridopsis villosa (Jurine), as 
defined by Brady, has a narrow and curved carapace, but more arched 
on the back and thicker in the middle than Fig. 11. The genus 
Cytherideis, of which only marine forms are known, offers a more 
convenient asylum for this narrow, curyed carapace with the ends 
equally rounded, but with an anterior compression of the valves 
1 Monogr. Post-Tert. Entom., Pal. Soc., and more lately treated of by Brady and 
Norman in Trans. R. Dublin Soe., n.s., vol. iv. 1889, p. 145, pl. xiv. figs. 26-27 ; 
and pl. xviii. figs. 25 and 26. 
* Quart Journ. Geol. Soc. vol. xli. 1885, p. 357, pl. viii. figs. 1-8. 
