no. 1600. ON THE REVISION OF PTERINEA GOLDFUSS— WILLIAMS. 89 
both well developed; anterior ear strong, distinctly separate from 
shell body; beaks protrude above the hinge line, that of left valve 
gibbous and larger than that of right valve; posterior margin of 
body protruding backward about the same distance as the posterior 
end of wing. Left valve ventricose, right valve convex but less so 
than the left. Ligament narrow and striate, developed both sides 
the umbone. Anterior muscular scar small but deeply incised, 
situated in front of the umbones at the base of foremost cardinal 
tooth between the ear proper and byssal sinus. Posterior muscular 
scar large and shallow, situated partly on body of shell, partly on the 
wing. Teeth several, varying in number (3 to 4); simple cardinal 
teeth; one or two lateral teeth situated near the edge of the hinge 
area and nearly, but not quite, parallel to it. Surface of left valve 
covered with rounded radial riblets, somewhat irregular, varying in 
size from fine lines to strong riblets, strongest on posterior half of 
body, either absent or only faintly marked on the wing or ear. Right 
valve either without radial sculpture, or radial lines or riblets 
obscure. 
The specimens of this species are abundant in the Chapman sand- 
stone on Presque Isle Stream, Chapman Plantation, Aroostook County, 
Maine, from which the type specimens here illustrated came. 
CORNELLITES, new genus. 
Type.—Pterinea fasciculata Goldfuss. 
Generic diagnosis—A strongly marked Pterinoid shell with gib- 
bous, rather narrow oblique body (left valve) ; large ear, set off from 
body by well defined sulcus; a large, broad flat wing, abruptly set off 
from body; the right valve slightly convex in umbonal region, flat to 
resupinate ventrally. Ligamental area striate; both cardinal and 
lateral teeth present; posterior muscular scar distinct and anterior 
muscular scar smaller and strongly impressed. 
The surface marked by a few strong radial ribs, with generally 
finer radial lines between them, and the fine concentric lamellae of 
growth generally evident over the radial sculpture. The radial sculp- 
ture covers the body and both wing and ear of the left valve in the 
type species. In other species which may be referred to the genus 
the sculpture on the ear is restricted to concentric lines‘ of growth, 
and the radial markings on the wings may be obscure. The right 
valve generally lacks radial sculpture except on the posterior wings 
where it is obscure; occasionally the stronger radial ribs are evident 
upon the body of the right valve. 
The name Cornellites is given in honor of Ezra Cornell, the founder 
of Cornell University, at which institution this description is written. 
The well marked section of the original genus Pterinea is represented 
by the species Pterinea fasciculata Goldfuss and P. costata Goldfuss. 
