MOLLUSCOIDEA. 3^3 



which reach to the umbo, besides several short intercalated 

 ones near the front margin; internally a medium septum is 

 strongly developed. 



Remarks. This species has not been met with in the recent 

 collections, and was originally described from a single, somewhat 

 imperfect brachial valve. It is undoubtedly allied to C. beecheri, 

 with which it is associated, but it appears to be distinguished 

 from that more frequent species by its larger size and its more 

 nearly orbicular outline. 



Formation and locality. Vincentown limesand, Vincentown 

 (Clark). 



Geographic distribution. New Jersey. 



Sub-family DALLININAE. 



Genus PLATIDIA Costa. 



Platidia cretacea n. sp. 

 Plate XXVII., Figs. 18-19. 



Description. Shell minute, the dimensions of the largest spe- 

 cimen observed being: Length, 1.76 mm. ; and width, 1.66 mm. ; 

 subovate jn outline with the valves subequally depressed convex, 

 so that the form of the entire shell is lenticular. Surface of the 

 valves smooth, the shell structure minutely punctate. Pedicle 

 valve with a prominent cardinal area which is bisected by a large 

 open foramen ; brachial valve with a large pedicle incision about 

 equal in size to that of the opposite valve. Internal features of 

 the shell not observed. 



Remarks. This little brachiopod shell occurs rarely in the 

 washings from the Vincentown limesand. It resembles P. mary- 

 landica from the Eocene of Maryland, but is much smaller. 



Formation and locality. Vincentown limesand, Vincentown 



(154). 

 Geographic distribution. New Jersey. 



