15 



Found by K. A. Blair, S. A. Miller and Mies Jessie Blair, in 

 whose honor we have proposed the specific name, in the Chouteau 

 limestone, near Sedalia, Missouri, and now in the collection of S. 

 A. Miller. 



Family MODIOMOBPHID^. 



ELYMELLA M1SSOURIENSIS, n. Sp. 



Plate II, Fig. It, left valve; Sig 12, cardinal view of a cast 



Species medium size. Shell subelliptical, narrower in front. 

 Length twice as great as the height. Cardinal line straight pos- 

 terior to the beaks, but abruptly dropping in front. Anterior end 

 narrowly rounded. Posterior end broadly rounded. Basal margin 

 rounded more gently at the anterior than at the posterior end. 

 Lunnule deeply impressed. Posterior cardinal slope concave. 

 Valves convex and somewhat gibbous in the umbonal region. 

 Beaks at the anterior end rounded and incurved over the cardinal 

 line. Umbones high and broadly rounded. Posterior umbonal 

 slope subangular at first, but the angularity gradually fades away 

 and the umbonal ridge is merged into the general convexity of tl e 

 shell. Surface marked by fine concentric striae growth. 



There may be some doubt about the reference of this species 

 to Elymella, as it is quite distinct from the forms Hall referred 

 to that genus. But we think it resembles Elymella more than 

 Modiomorpha and it certainly belongs to one of the genera. In 

 fact Hall only regarded Elymella as a subgenus of Modiomorpha 

 but we prefer to treat them at present as distinct genera. 



Found by B. A. Blair in the Chouteau limestone, near Sedalia, 

 Missouri, and now in the collection of S. A. Miller. 



OYPMCARDELLA EXIMIA, n. sp. 



Plate II, Fig. 25, left valve with posterior end broken off. 



Species medium size. Shell subrhomboidal to subtriangular. 

 Length one-half greater than the height. Anterior end abruptly 

 truncated anterior to the beaks and then prolonged at the antero- 

 basal extremity and abruptly rounded into the basal margiu. Car- 

 dinal line arcuate. Posterior margin obliquely Iruncaied, pro- 

 longed at the post basal extremity and rapidly rounded iuto the 

 basal margin. Basal margin broadly and regularly rounded. 

 Beaks at the anterior end and obtuse. Umbones prominent Urn- 



