210 PALEOZOIC PALEONTOLOGY. 
Remarks.—This species differs from any of the described species of 
the genus in its marginal row of tubercles upon the right valve. The 
specimens studied range from 1 mm. to 3 mm. in length, but scarcely 
vary in their proportions. The right valve of the species closely 
resembles, in its form and ornamentation, the left valve of Aparchites 
granilabiatus Ulr.,* but the left valve of this New Jersey species is 
quite different from that of Ulrich’s species. Furthermore, the free 
margin of the left valve of the species here described overlaps. the 
margin of the right valve, this being a character which would exclude 
it from the genus A parchites. 
EURYCHILINA OCULIFERA Nn. SD. 
Plate XIII., Fig. 16. 
Carapace subelliptical; valves moderately convex, with a nearly 
central, subcircular pit surrounded by a slightly-elevated rim, with 
a slight prominence obliquely above and to the front of it. Mar- 
ginal area convex, separated from the body of the valve by a sharply- 
impressed groove, the free margin extended into a narrow frill. Sur- 
face nearly smooth, the marginal border and frill marked by obscure, 
radiating lines. 
The dimensions of a rather large specimen are: length, 2.7 mm.; 
height, 1.8 mm.; length of hinge-line, 2 mm. 
Remarks.—This species may be distinguished from most other mem- 
bers of the genus by its sharply-defined, subcentral pit, which is not 
connected with the dorsal margin by a sulcus. In this character, how- 
ever, it resembles H. solida Reudemann, but may be distinguished from 
that species by its greater obliquity and its smooth surface. The next 
species resembles /. solida more closely than this one. 
EURYCHILINA JERSEYENSIS MN. Sp. 
Plate XIII., Fig. 17. 
Carapace subelliptical, moderately convex, with a subcentral, nearly 
circular pit, surrounded by a slightly-elevated rim, not connected with 
the dorsal margin by a sulcus. A slight prominence lies obliquely 
* Pal. Minn., pt. II., p. 644, pl. 45, figs. 21-28. 
