maa 
New and Little Known American Paleozoic Ostracoda. 123 
with the dorsal and ventral margins sub-parallel. Dorsal edge 
straight and long, terminating abruptly, the antero-dorsal angle 
perhaps a little the most acute; ends uniformly and nearly equally 
convex; ventral edge very gently convex. Edges without a flange. 
Ridge large, peculiarly modified, digitate, and occupying nearly 
two-thirds of the surface of the valve. The posterior half is 
divided so as to appear like two fingers separated by a sulcus 
nearly as profound as the median one. ‘The anterior half is wide 
and swollen on the outer side, while the ventral portion is thick 
and surmounted by a thin longitudinal crest. 
eizeweeneth, 1.46 mm.; height, o.82 mm.;. thickness, 0.33 
mm. 
The outline of this species is not unlike that of /. pedigera, but 
the ridge in the two species is totally different. Indeed, some 
may be inclined to question that the two are congeneric, but I do 
not think such a doubt can prevail, since the next species is clearly 
intermediate in character. 
Position and locality: I have seen only the example figured 
which I collected in Marion County, Ky., from the upper beds of 
the Cincinnati Group. The specimen is attached to a fragment of 
Fleterospongia. 
JONESELLA CRASSA, N. sp. 
Plate Vil figs. 11a, 03. 6 
Carapace oblong, widest posteriorly, slightly oblique, the ante- 
rior margin being most produced above the middle. Dorsal mar- 
gin straight, the junction with the ends obtusely angular. Posterior 
edge uniformly convex, the ventral straightened in the middle. A 
well-developed flange around the free edges. Ridge loop- or 
horseshoe-shaped, oblique, very thick, the ventral portion over- 
hanging the edge of the valve, the anterior arm very prominent 
below, bifurcating above, one division vertical and terminating 
knob-like on «the dorsal border just in front of the center, while 
the other division soon becomes obsolete. ‘The posterior arm, sit- 
uated close to the margin of the valve, appears to consist of two 
parts toward its upper extremity, or as though one ridge was 
planted upon another, with the lower one extending almost to the 
dorsal margin. 
