NATURAL SCIENCES OF PHILADELPHIA. 13 



Length -80 (100) ; height -62 (77) ; thickness of both valves -40 (50). 

 Resembles E. nuptialis in form, but it is less ventricose around the margin. 

 and is further distinguished by its radiating strife. 



Edmondia ^eqdimarginalis, Win., (=Cardinia xquimarginalis, Win., Proc. 

 Acad. Nat. Sci. Phil., Sept , 18G2, p. 413.) The identification with the Michigan 

 species is quite conclusive, but the better state of preservation of this fossil 

 necessitates a correction of the generic reference. 



Edmondia (?) bicarinata, n. sp. Shell rather small, transverse, oblong, a 

 little the widest at the posterior extremity of the straight, lengthened hinge- 

 line ; dorsal margin erect, not inflected ; ventral margin subparallel with the 

 dorsal, having a distinct shallow sinus near the middle, which leaves a dimin- 

 ishing furrow extending to the beaks ; angularly rounded to the extremities, of 

 which the posterior is truncate by a slightly curved line at right angles with 

 the hinge-line, and another above this forming an ang'e of about 135 with 

 the hinge-line. Beaks one-fifth the length of the shell from the anterior end, 

 somewhat flattened, and incurved over a deep, distinct lunette. Greatest con- 

 vexity one-third the distance from the dorsal to the ventral sides. A strong 

 angular ridge extends from the beaks to the posterior ventral angle, and 

 another, less conspicuous, to the angle connecting the two posterior truncated 

 margins. Surface marked by fine incremental lines, parallel to the basal and 

 posterior borders. 



Length -59 (100) ; height -27 (41) ; thickness of both valves -12 (20). 



Edmondia (?) elliptica, n. sp. Shell rather large, appressed, transverse, 

 with an elongate-elliptical outline. Beaks flat, inconspicuous, situated one- 

 fifth the shell-length from the anterior end. Hinge margin elongate, slightly 

 curved, abruptly elevated ; a flattened area extending from the beaks back- 

 ward to the posterior hinge angle. Extremities neatly rounded. Surface 

 marked by numerous distinct unequal lines running parallel with the pallial 

 margin. 



Length 1-36 (100) ; height -65 (48). 



SANGUINOLITES, McCoy. 



Sanguinolites amygdalinus, n. sp. Shell of medium size, equivalve ; length 

 equal to two and a half time3 the height ; beak about one-fourth the length 

 from the anterior end, scarcely elevated above the hinge, somewhat depressed, 

 incurved ; dorsal margins slightly concave, posteriorly inflected inwards, form- 

 ing a deep escutcheon ; ventral margin gradually curved along the middle, 

 more rapidly so toward the extremities ; posterior extremity describing nearly 

 a semicircle, and joining the dorsal line by a very easy angle ; anterior extrem- 

 ity abruptly rounded to the deep, broad lunette, which reaches from the beak 

 to the middle of the shell. Greatest protuberance one-third the distance from 

 the beak to the venter, rather tumid ; an obtuse angulation extending from the 

 beak to the postero-basal angle; a strong internal ridge running near to, and 

 parallel with, the hinge-line. Surface marked by strong concentric wrinkles, 

 which nearly disappear in the dorsoumbonal region. A shallow sinus in front 

 of the mid-ventral margin, which can be traced upward toward the beak. 



Length -97 (100) ; height -44 (45) ; distance of beak from anterior end -25 

 (26) ; from posterior -72 (74) ; thickness of both valves -36 (37). 



Somewhat resembles Allorisma Hannibalensis, Shum., but differs in the ab- 

 sence of the "broad concentric ribs" of that species. It less resembles the 

 Burlington fossil, usually referred to the same species. 



Sanguinolites cylindricus, n. sp. Shell small, equivalve ; length equal to 

 two and a half times its height; beak about one-seventh the length from the 

 anterior end, elevated above the hinge-line, flattened and enrolled; greatest 

 height along the perpendicular from beak to base; dorsal margin extended, 



1862.] 



