DESCRIPTIONS OF INVERTEBRATE FOSSILS. (U 



This Tellimi is closely related to T. equilatevdUs, M. aiicl 

 H., of the Fox Hills division of the upper Cretaceous; but 

 comparison of the Denison specimens with Meek's Hiijares of 

 that species shows that they represent a decidedly more 

 elongate form than the latter. 



CORBULA CRASSICOSTATA, Sp. noV. 



Shell triangular-ovate, gibbous, nearly as broad as high, 

 short; gaping posteriorly by a short, conically inflated, gently 

 truncated rostrum, which is jjlaced high above the base of 

 the shell; undjones placed in advance of the middle, that of 

 the right valve only moderately high arched, its summit ob- 

 tuse; surface ornamented with very coarse, flattish-topped, 

 concentric ribs, separated by abrupt, deep, narrow intervals. 

 There are seven or eight of the ribs on the basal half of a 

 right valve the same number of millimeters high. 



Mi'dsuremeiifs. — Height 7.5, length 10, breadth about 

 7 mm. 



Occurrence. — In arenaceous limestone bands of the Kiowa 

 shales, at Belvidere, Kansas; in Nos. 2-4 of the writer's 

 •'Belvidere Section." 



So far as the writer can judge from material now in hand, 

 the similar Corbiila that abounds in the condition of casts 

 and molds in the ochraceous shell-conglomerate of the Deni- 

 son beds, at Denison, Texas, presents no differences of specific 

 value from the Kansas shell above described. The casts 

 show that the pallial line is very sharply impressed. 



Margarita brownii, sp. nov. 



Shell of moderate size and thickness, the postlabial region 

 becoming thicker at maturity, depressed-conical, deeply um- 

 bilicated; whorls four and a half, somewhat depressed, rounded, 

 smooth, the body-whorl obtusely angulated behnv, becoming 

 much thickened and tumid on the part near the aperture, the 

 tumid portion, however, flattened a little on the quarter be- 

 tween base and umbilicus; aperture round, much smaller 

 than the nearly oblong and sharpened peristome, the latter 

 being continuous except on about one-fifth of the circuit, and 



