268 The American Geologist. NovemixT, isna 
A^tilvcs broadly suhclliptical.scaxx'ely obliciue. the ends strongly 
rounded, nearly e(jual. the ventral margin uniformly and more 
than usually convex. Free edges, except in the cardinal regions, 
set with small hut {)rominent papillae. Surface minutely punctate, 
ventricose in the lower half, flattened in the upper; with point of 
greatest convexity much beneath the middle. A faint smooth 
(non-punctate) spot occui's just in front and above the center. 
This s[>ecies might with others described in this paper be placed 
with Aparchites, Jones, but there is something so peculiar about 
Prof. Jones" type of the genus and one or two undoubtedly con- 
generic species, that I hesitate to enlarge the limits of the genus 
beyond them. 
Formation and locality: Rare in the upper part of the Trenton shales 
(Phylloporina beds) at St. Paul, Minn. 
Lepepditia millepunctata, n. sp. 
Fl.vte IX. Figs. H7 to 39. 
Leu nth, of a right valve, 1.57 mm.; hight 1.0 mm.; greatest thickness 
0.45 mm. 
This species is very similar to L. itqai/atera of this paper, but 
I have no doubt of tlieir specific distinctness. There is a-'slight 
channel and rim about the free edges Avanting in that species, 
while the surface also is very finely punctate, and more uni- 
forndy convex, the profiles of the two forms l)eing ditferent. The 
present species again is a little higher. 
It is possilile that this species should be placed with IsoclnJimi 
rather than Lcpcnltt ia. \mi as near as can be determined from the 
material at hand it appears that the Aah'es overlap slightly, the 
left over the right, along the ventral border. 
Formation and loe ility: Trenton shales, one mile east of Fountain, 
iMinnesota. Rare. 
Leperditia fimbriata, n. sp. 
Plate ix. Figs. ?A to oG. 
Length, of a right valve, (excluding spines) 1.88 mm.; hight 1.23 mm.; 
thickness 0.44 mm. Length of dorsal edge 1.2 mm. 
Valves sul)oval, moderately and almost uniformly convex, the 
ends nearly e(pially rounded, the posterior a little the wider. 
Extremities of dorsal edge angular, the posterior somewhat prom- 
inent. Point of greatest convexity slightly lielow the center. 
The entire ventral border and the ends, excepting the upper third 
on each side, with a fringe consisting of long, almost paliform. 
