378 CRETACEOUS PALEONTOLOGY. 



Leda gabbana (Whitfield). 

 Plate XXIX., Figs. 28-30. 



i860. Leda protexta Gabb, Jour. Acad. Nat. Sci. Phil., 2nd 

 ser., vol. 4, p. 397, pi. 68, fig. 35. (Not L. protexta 

 Gabb, Jour. Acad. Nat. Sci. Phil., 2d ser., vol. 4, p. 

 p. 303, pi. 48, fig. 23.) 



1886. Nucudana Gabbana Whitf., Pal. N. J., vol. i, (Monog. 

 U. S. G. S., vol. 9), p. 106, pi. II, figs. 11-13. 



Description. — "Shell of moderate size, extremely elongated, 

 the length being nearly twice and a half the extreme height. 

 Valves convex, regularly and evenly rounded. Beaks small, ap- 

 pressed and incurved, and distinctly inclined toward the narrower 

 end of the shell, scarcely rising abo've the hinge-line on the wider 

 part, and situated about two^fifths of the length from the larger 

 end. Cardinal margin on the wider end gently arcuate and a 

 little more strongly concave on the narrower side of the beak; 

 large extremity of the shell sharply rounded ; basal margin gently 

 rounded throughout and the posterior end narrow and rounded. 

 As the specimen is an internal cast, it preserves no evidences of 

 the surface characters. The muscular scars are extremely faint 

 and the pallial line undistinguishable, although the cast is in 

 an excellent state of preservation and somewhat polished on the 

 surface from the perfect condition. The hinge-line has been 

 marked by a large number of very fine teeth, gradually increasing 

 in size from the center outward. On the wider end of the shell 

 there are about 25 visible under a glass and about 20 somewhat 

 stronger ones on the narrower side of the beak. The ligamental 

 pit has been of moderate size, but well marked and deep." 

 (Whitfield.) 



Remarks. — ^This species has not been met with in the recent 

 collections of the Survey, and the type specimen which is said 

 by Whitfield^ to be preserved in the collection at Trenton, has 

 apparently been lost or destroyed. The specimens in the recent 

 collections which most nearly approach Whitfield's figure of this 



'Ann. N. Y. Acad. Sci., vol. 12, p. 161. 



