416 PROCEEDINGS OP THE ACADEMY OP 



Locality. Union, Branch county, in blue argillaceous shales of the Huron 

 group. 



This fossil may be a Grammysia, but it is destitute of the oblique furrows 

 considered characteristic of that genus. 



It bears a remote resemblance to Sanguinolites (Leptodomus) costellatus, 

 McCoy. 



Cardiomorpha, de Koninck. 



Cardiomorpha modiolaris, n. sp. Shell rather small, vertically ovate, in- 

 flated, equi valve, with very short hinge line, and very symmetrical extremi- 

 ties. Hinge line blending by a regular curvature with the posterior margin ; 

 both margins approximately parallel, gradually curved, and connected by the 

 more rapidly curved respiratory border. Beaks scarcely projecting beyond 

 the hinge, obtusely pointed and straight ; valve inflated and convex to the 

 pallial border, slightly flattened on the anterior umbonal slope. Surface 

 smooth, with a few coarse concentric folds marking the later growth. 



Length from the extremity of the beak over the umbonal slope 1*05 (100) ; 

 shortest distance from this line to extremity of anterior margin *34 (32) ; to 

 posterior margin *40 (38). 



Localities. Section 27, Columbia, Jackson county ; Moscow, Hillsdale 

 county, and Marshall and Battle Creek, Calhoun county. 



The hinge characters of this species not being known, its generic identity 

 may be questioned. The beak and hinge line do not present the characters 

 of the typical Cardiomorpiia, but the shell presents strong analogies with C. 

 livida, de Kon., (Anim. Foss. 106, pi. iii., 4), from which it differs only in 

 being more equilateral and in having its beaks more separated. 



Cardiomorpha Julia, n. sp. Shell small, luciniform ; beaks moderately 

 produced, small, appressed turned forward, somewhat anterior to the middle of 

 the shell ; posterior hinge s,lope nearly straight, making a very obtuse angle 

 with the posterior margin, which is also nearly straight, and connects by an 

 abrupt curve with the ventral border. Anterior hinge slope making an angle 

 of about 118 with the posterior, uniting by an abrupt curve with the regu- 

 larly convex ventral border. The hinge has not been fully examined, but a 

 couple of fine sharp laminae are seen proceeding from beneath the beak, along 

 the posterior hinge plate. External surface marked by sharply cut concentric 

 striae, at regular intervals, which increase gradually in width with the growth 

 of the shell. 



Length from anterior to posterior angulation *S5 (100) ; height from beak 

 to ventral margin *64 (75, ; radius of curvature of ventral side - 48 (56) ; 

 bringing the centre of curvature on the postumbonal slope "17 from the beak ; 

 convexity of right valve '12 (14) ; number of concentric striae on the mea- 

 sured specimens about 45. 



Localities. Battle Creek, Marshall, Moscow. This seems to be a close rep- 

 resentative of C. Puzosiana, de Kon. (Anim. Foss. 104, pi. ii., 8), and only 

 differs in more angulated extremities and more regular striation ; though an 

 occasional specimen has more rounded extremities. This species recalls also 

 the forms figured by Prof. Hall, under the names Lucina ? retusa and Unyu- 

 lina [Lucina?] suborbicularis, (Greol. Rep. 4th Dist., N. Y., pp. 243, 245), from 

 the Portage group. While the Michigan fossil is more transverse than the spe- 

 cimens figured by Prof. Hall, it may yet prove identical. 



Cardiomorpha capuloides, n. sp. Shell very small, with a very prominent 

 umbo ; body and margin of each valve trumpet shaped, giving it the appear- 

 ance of a capuloid shell. Beak slightly anterior, turned forward, and in the 

 cast obtuse, with a terminal callosity, as if by the absorption of the shell- 

 substance separating the extremity of an enrolled beak from the body of the 

 mollusc. Body of shell more extended posteriorly ; autumbonal slope rather 

 rapid ; margin nearly circular or a little ovate. Hinge and external surface 

 unknown ; cast smooth, with a few concentric wrinkles of growth. 



[Sept. 



