NATURAL SCIENCES OF PHILADELPHIA. 
417 
Length from extremity of beak over umbo to ventral margin *35 ; antero¬ 
posterior dimension *29 ; elevation of umbo above plane of valve *20. 
Locality. —Grindstone quarries, Pt. aux Barques, with Rhynchonella cameri- 
fera, &e. 
None of my specimens of tbis singular shell are perfect, even as casts ; and 
I should be induced to refer them to Platyceras, Conrad, were it not that five 
would thus be sinistral and six dextral, while at the same time the very cam- 
panulate aperture seems to suggest rather Cardiomorpha or Isocar dia, 
Cakdiopsis, Meek and Worthen. 
Cardiopsis crenistriata, n. sp.—Shell of medium size, gibbous ; hinge line -j 
straight, rather short, joining the posterior margin by a regular curve which J 
proceeds to the ventral side where a more abrupt curvature separates the pos-f 
terior from the anterior border. Beak prominent, incurved, projecting a little'/ 
above,the hinge line. Surface marked by a set of irregular concentric wrinAj 
kies, and a set of fine, regular raised concentric striae, the whole decussated ( 
by conspicuous, radiating, unequal, wrinkled ribs, which are fine and some- \ 
what regular on the beak, becoming irregularly crenulated in the middle of 1 
the valve, and irregularly flexuous near the pallial border. I 
Greatest length from the beak to the ventral margin over the umbonal slop#' 7 
•96 (100) ; angle between this and the hinge margin 55° ; convexity of left 
valve *33 (34). 
Locality. —Section 27, Columbia, Jackson county. 
This fossil differs from Cardiomorpha radiata, de Kon., (An. Foss. 109, pi. 
ii., 6), in being less inflated all around the pallial region, and in being more 
produced posteriorly, as well as in the characters of the striation. It proba¬ 
bly agrees in generic characters. Its closest analogue is Cardiopsis radiata, 
Meek and Worthen, (Proc. Acad. Nat. Sci., Phil., Oct., 1860, and June, 
1861), = Megambonia Lyoni, Hall, (13th Rep. Reg. N. Y., p. 110), from which 
it seems to differ only in its striation. 
Cardiopsis jejuna, n. sp.—Shell small, somewhat orbicular, nearly equila¬ 
teral, with a prominent sharp beak slightly turned forward. Hinge line ob¬ 
tusely angulated beneath the beak, extending on each side to a subalate ex¬ 
pansion of the (right) valve, between which points the curvature of the pal¬ 
lial margin decribes about three-fifths of a circle. Beak projecting above the 
hinge; umbo excavated on the anterior side ; umbonal ridge tumid on the 
posterior side. Characters of hinge and external surface unknown ; surface 
of cast with a few concentric furrows. 
Length *38 (100) ; height *41 (108) ; distance from posterior extremity to 
line drawn over umbonal slope ‘23 (61); from anterior extremity to same line 
•20 (53) ; convexity of right valve *12 (32). 
Locality. —Railroad cut, three miles north of Napoleon, Jackson county. 
Cardiopsis megambonata, n. sp.—Shell very small, ovate, with an elevated, 
little incurved, nearly central beak, gibbous umbo and regularly rounded 
margins, of which the ventral is most abruptly so. Slopes from the umbo 
convex in all directions to the very margin. Anterior and posterior cardinal 
margins similar and equal. Surface of casts striately ribbed, most distinctly 
so toward the ventral border, and in some cases marked by rather strong con¬ 
centric wrinkles toward the pallial margin. 
Height from beak to ventral margin *25 (100); length from anterior to pos¬ 
terior margin *23 (92) ; convexity of left (?) valve *11 (44). 
Locality. —Grindstone quarries, Pt. aux Barques, with Rhynchonella earneri- 
fera, &c. 
Nucula, Lamarck. 
Nucula Hubbardi, n. sp.—Shell rather large, ovate-triangular, ventricose ; 
beaks three-fifths the shell-length behind the anterior (longer) extremity, 
1862 .] 
