22 Trans. Acad, Sci. of St. Louis. 



specimen observed is about 15 mm. in breadth, though most 

 of them are somewhat smaller. 



It is possible that these shells may be the young of Athyris 

 lamellosa which is associated with them. It also quite 

 strongly resembles the figures of Athyris hrittsi Miller, from 

 the Devonian near Otterville, Missouri. 



DiELASMA sp. 



Pl.IV.f. 9. 



A single imperfect pedicle valve of a species of Dielasma, 

 has been observed in the Northview fauna. It is a shell 18 

 mm. in length by about 15 in breadth, regularly convex from 

 the beak to the front margin and with no mesial sinus. It 

 resembles some of the figures of D. formosa* but it is pro- 

 portionately broader than that species. 



BRYOZOA. 



Bryozoans apparently belonging to Fenestella or to some 

 closely allied genus are not uncommon in the sandstone at 

 Northview, but their condition of preservation is such that no 

 identification of them can be made. 



MOLLUSC A. 



PELECYPODA. 



Crenipecten wiNCHELLi (Meek)? 



PI. IV. .15. 



Shell flabelliform, subequilateral, inequivalve, attaining a 

 height of 25 mm. in the larger specimens, the extreme length 

 about equal to or a little greater than the height. Basal 

 margin rounded, lateral margins rounded below but straight- 

 ened above : if continued to the beak they meet at an angle of 

 about 100^ or less. Hinge-line about or sometimes a little 

 more than two-thirds the greatest length of the shell. 



Left valve compressed-convex, the greatest convexity at a 

 point about two-thirds the distance from the basal margin to 

 the beak; the ears triangular, compressed, the anterior one 

 somewhat smaller and more abruptly flattened from the body 



* Pal. N. Y. %*,pl. 81. f. 12-26. 



