18 
PROCEEDINGS OF THE ACADEMY OE 
SANGUJINOLARIA, Lamarck. 
Sanguinolaria ? leptogaster, n. sp.—Shell small, thin, subquadrangular. 
Beaks subcentral, flat, not elevated above the dorsal line. Posterior end ob¬ 
liquely truncated ; anterior gently rounded below, abruptly above, with a 
long deep lunette ; ventral side arcuate in the middle, joining the extremities 
by a gradually increased curvature. Umbo flattened,—a low ridge extending 
obliquely to the posterior basal angle. Dorsal line straight behind the beaks, 
joining the posterior side at an angle of 125°. Surface marked by fine 
regular strise parallel with the ventral and posterior margins. 
Length *53 (100); height *38 (71) ; thickness of valves *09 (17). 
BELLEROPHON, Montfort. 
Bellerophon cyrtolites, Hall, (Thirteenth Rep. Reg. N. Y., p. 107).—A 
small Bellerophon, laterally appressed, and with an acute periphery, ap¬ 
proaches too closely to B. cyrtolites to justify discrimination. It is known, 
however, only by its cast, which is quite smooth. Should the identification 
prove correct, this species occurs at Rockford, Ind., Marshall, Michigan, and 
Burlington, Iowa. 
PORCELLIA, Leveille. 
Poecellia rectinoda, n. sp.—Shell small, gradually enlarging, marked by 
a series of transverse nodes, which are strongest on the dorso-lateral region, 
and gradually diminish to the middle of the side ; transverse section between, 
two nodes subcircular. Dorsum unknown. 
Diameter of last whorl about *59 ; dorso-ventral diameter of tube near the 
aperture *19. 
This species differs from P. crassinoda, White and Whitefield, in its circu¬ 
lar section and transversely elongate nodes—fromP. obliquinoda, White, in the 
transverse position of the nodes—and from P. nodosa , Hall, (Greol. Surv. Ia., 
Supplem. to vol. i. part 2, p. 92), in its much smaller size and different 
geological horizon,—the latter being found in the upper bed of the Burlington 
limestone, which has thus far furnished no species identifiable with fossils 
from the sandstones below. 
DENTALIUM, Linnaeus. 
Dextalium geandjevum, n. sp.—Shell rather large, perfectly straight and 
terete, or a little compressed ; tapering *09 in one inch near the larger end, 
less rapidly near the small end ; surface marked by faint, irregular incremen¬ 
tal striae, which run obliquely around the shell, and in flattened specimens 
are most advanced along one edge. 
Length of largest specimen 2-18 ; diameter at larger end *21 ; at smaller end 
about *05. 
This species resembles D. venustum , Meek and Worthen, (Proc. Acad. Nat. 
Sci., Phila., June, 1861, p. 145), from the St. Louis and Spergen Hill lime¬ 
stones. The latter, however, tapers but *075 in one inch, and is described as 
“nearly” straight and quite smooth, while the present species is rigidly 
straight and transversely striated. 
PLATYCERAS, Conrad. 
Platyceras cornuforme, n. sp.—Shell small, describing about half a whorl, 
very rapidly enlarging, similarly curved throughout, broadly and obtusely 
carinated, when young, along the peripheral line; transverse section becoming 
subsequently nearly circular; aperture a little oblique to the whorl, with a 
somewhat sinuous peristome,—the principal sinus being just beneath the mid¬ 
dle of the outer lip. Surface marked only by strise of growth, which curve 
forwards on the sides, and backwards along a belt just beneath the periphery. 
The shell is nearly symmetrical and its curvature planorboid. The apex is 
blunt and not perceptibly turned to the right or left. 
[Jan. 
