638 THE PALEONTOLOGY OF MINNESOTA. 
(Leperditella macra. 
is a very distinct species, there is probably not much danger of confusion between 
them. 
Formation and locality.—Middle third of the Trenton shales, Minneapolis, Minnesota. 
. 
LEPERDITELLA MACRA, 72. Sp. 
PLATE XLIII, FIGS. 7—9. 
Size.— E. C.) Length 1.4 mm_., hight 1.08 mm.; thickness 0.55 mm. 
Carapace short, scarcely oblique, subovate; dorsal margin straight, four-fifths of 
entire length of carapace, angles distinct; ends subequal, rounding almost uniformly 
into the basal outline; carapace moderately convex except in the anterior third, which 
is strongly compressed, giving a very unusual ventral and dorsal profile; anterior 
edges thickened, ventral overlap strong; surface smooth. 
This species is remarkable for its compressed anterior part, and for its short 
form, in neither of which features it is equalled by any leperditoid ostracode known 
to me. ~ 
Formation and locality—Middle third of the Trenton shales, Minneapolis, Minnesota. 
LEPERDITELLA GERMANA Ulrich. 
PLATE XLV, FIGS. 24—26. 
Leperditia germana ULRicn, 1892, American Geologist, vol. x, p. 266. 
Size.—(L. V.) Length 2.17 mm.; hight 1.4 mm.; thickness 0.67 mm. 
Carapace subovate, ends nearly equal, the posterior somewhat the wider; back 
straight for about four-fifths of the entire length, dorsal angles well marked; ventral _ 
outline somewhat oblique, most prominent just behind the center; edges rather blunt, 
with a narrow groove or rim along the free margins of the left and perhaps of both 
valves. Surface with the greatest convexity in the posterior half, and a broad, 
undefined depression in front of the center of the dorsal slope. 
This form is closely related to L. mundula and L. inflata, two species from the 
lower division of the Birdseye limestone in Kentucky. From the first it differs in 
having the ends more equal, the edges blunter, and the surface more convex in the 
dorsal half. The narrow marginal rim is wanting in that species, and instead of a 
simple dorsal depression, that form has'a low elevation in the lower part of it. The 
second differs chiefly in the greater inflation of the posterior half of its dorsal region. 
Formation and locality.—This species has so far been met with only in the Lower Blue limestone of 
the Trenton at Mineral Point, Wisconsin, and Dixon, Illinois, but we know of no reason why it should not 
occur also at Minneapolis and other localities in the state. 
