1903.] NATURAL SCIENCES OF PHILADELPHIA. 263 



near vicksburgensis, if I have identified it correctly from the published 

 drawing, the latter being about twice as large as any of my specimens, 

 but agreeing perfectly otherwise. 



Tellina pilsbryi n. sp. 



There is an undescribed Tellina occurring in large numbers in the 

 Lower Vicksburg, to which I take pleasure in giving the above name 

 in honor of Dr. H. A. Pilsbry, of Philadelphia. It is strongly inequi- 

 lateral, trigonal, with the ventral edge rounded, rather thick in sub- 

 stance, compressed, the anterior and posterior sides broadly rounded, 

 the surface equally declivous and convex toward the edges and not 

 more abruptly declivous along the anterior edge ; it is strongly marked 

 with fine, very close-set concentric striae throughout. The lateral teeth 

 of the left valve are large and strongly developed, those of the right 

 obsolescent. The larger cardinal of the left valve is subbifid. The 

 length of a nearly full-grown valve is 9 mm.; height about 7 mm.; 

 beak about 2 mm. in front of the median line. The lunule is small 

 and slender. 

 Lucina vicksburgensis n. sp. 



Occurs in the Lower Vicksburg in great abundance. This species 

 is subec|uilateral, suborbicular, rather compressed, the beaks somewhat 

 high and acute, the adjacent anterior sinus small and deep, the lunule 

 small and deep-set and but little more than twice as long as high as 

 a rule. The surface is covered throughout with strong concentric raised 

 lines which are close-set and low, but becoming strongly lamelliform on 

 the anterior and posterior dorsal declivities, the dorsal edge being ren- 

 dered rough spiculose and uneven thereby. Cardinal tooth of right 

 valve very oblique. Length 7^ mm. ; height 7^ mm. It grew some- 

 what larger than the type above described, but never exceeded this 

 length by more than about 2 mm. It might be considered closely allied 

 to the Jacksonian Cijdas curtus of Conrad {Am. Journ. Cone, I, p. 139), 

 as the posterior side is noticeably more truncate than the anterior, 

 were it not for the fact that curtus is described as "ventricose," a term 

 which could not possibly be applied to vicksburgensis. 



Lucina scopularis n. sp. 



Red Bluff formation. Approaches vicksburgensis very closely, 

 being orbicular and only moderately convex, but it is a little smaller 

 and the concentric lines are finer, relatively less close-set and more 

 lamelliform, becoming still more strongly so on the anterior and 

 posterior dorsal declivities, though relatively less strongly so than 

 on the corresponding parts of vicksburgensis. It differs principally 



