268 TRANSACTIONS OF THE [MAR. 15, 



more rapidly posteriorly into the posterior margin, which is 

 sharply rounded dorsally. 



Surface nearly smooth, but showing some inconspicuous 

 wrinkles of growth. 



This specimen is almost certainly not a Schizodus, but as it 

 seems difficult to place itinan}- genus with certainty it is placed 

 here provisionally. 



Sanguinolites? sp? 

 PL XXL, fig. 6. 



Shell elongate sub-ovate in outline, moderately convex along 

 the umbonal ridge. Beaks depressed, situated at a point about 

 one-fourth the distance from the anterior to the posterior ex- 

 tremities of the shell. 



Hinge-line straight, about two-thirds the length of the shell. 

 Anterior margin of the shell sinuate just below the beaks, regu- 

 larl}^ rounded below. Ventral margin straight or slightl}' arcu- 

 ate. Posterior margin rather sharpl}' rounded. 



Surface smooth except for some indistinct concentric lines of 

 growth. 



This species occurs rather abundantly, but the specimens are 

 all so poorly preserved that the characters can be but imper- 

 fecth' recognized. The specimens are placed provisionally in 

 the genus Sanguinolites, but more perfect materialmust be studied 

 for the accurate determination of their characters. 



GASTROPODA. 



Capulus acutirostris Hall. 



1856. Capulus acutirostris, 'iiii\\,Triins. Albany Inst.,Vol. 4, p. 31. 

 1858. Capulus acutirostris, Hall, Geol. Iowa, Vol. 1, pt. 2, p. 

 665, PI. 23, figs. 14a-b. 



1882. Platyceras acutii-osfr-is, Whitfield, Bull. Am. Mus. Nat. 

 Hist., Vol. 1, p. 67, PI. x, figs. 13-15. 



1883. Platyceras acutirostris. Hall, 12th Rep. Geol. Surv. Ind.. 

 p. 370, PI. 31, figs 13-15. 



1890. Capulus acutirostris, Keves, Proc. Acad. Nat. Sci., Phil., 



p. 170. 

 1894. Orthonychia acutirostre, Keyes, Mo. Geol. Surv., Yol. 5, 



p. 190, PI. 54, figs. 2a-c. 

 A single specimen in the collection agrees well with the fig- 

 ures and descriptions of Capulus acutirostris. It is imperfectly 

 preserved, but seems referable to this species. 



