MARYLAND GEOLOGICAL SURVEY 105 



Cythere paucipunctata n. sp. 

 Plate XXXVIII, Figs. 7-9. 



Description. — Carapace rather large, strongly convex, subelliptical in 

 outline. Left valve with the ends subequal, slighth" obliqne, the curve 

 of the anterior edge being a little sharper in the ventral half than in 

 the upper, while the latter merges very gently into the straight dorsal 

 outline; posterior margin with its greatest prominence and curve just 

 above the mid-height, below passing gradually into the convex ventral 

 outline, above turning more rapidly forward to the distinct though 

 obtusely angular junction Avith the hinge line; ventral edge tumid, 

 slightly overhanging the contact margin. Surface smooth except on 

 the most convex portion, which lies a little behind the center of the 

 valve. Here there are three rows of rather large and sometimes not 

 very closely defined pits, three to five in each row. Eight valve un- 

 known, probably narrower than the left and varying similarly in shape 

 as in related species. 



Length of an average left valve 1.15 mm., height of same 0.61 mm., 

 greatest thickness of same 0.32 mm. 



This and several of the preceding species, notably C. hurnsi and 

 C. pleheia, are American representatives of the well marked section of 

 the genus of which the common European Tertiary C. jurinei Miinster 

 is a good type. C. paucipunctata is distinguished from all the other 

 Tertiary species of the section by slight peculiarities in its outline, 

 greater convexity, and the limited number of surface pits. 



Occurrence. — Choptaxk Formation. Peach Blossom Creek, 3 miles 

 southwest of Easton. 



Collections. — U. S. Xational Museum, Maryland Geological Survey. 



Cythere tuomeyi n. sp. 

 Plate XXXA'III, Figs. 4-6. 

 Description. — Carapace moderately convex, subovate; anterior end 

 considerably wider than the posterior, somewhat oblique, with the 

 greatest prominence and ciirve in the lower half, the upper half merging 

 more gradually into the straight dorsal margin; posterior margin 

 rounded; cardinal angles obtuse, the anterior one, especially in the right 



