MARYLAND GEOLOGICAL SURVEY 653 



cular scar. Muscular impressions strong and about equal in size. Inner 

 margin of the free edge of the shell crenate. The above description is 

 based largely upon a very perfect right valve from the Marshalltown clay 

 marl near Swedesboro." Weller, 1907. 



The species has a very meager representation in Maryland, and is, appa- 

 rently restricted in its distribution to the Matawan. It differs from 

 C. vadosus Morton, so prolific in the Monmouth of Maryland and the Gulf, 

 in its more compressed valves, less anterior umbones, and much lighter 

 shell, with the consequently thinner hinge plate and less pronounced pos- 

 terior keel. 



Occurrence. MATAWAN FORMATION. Ulmstead Point, ? Arnold 

 Point, Anne Arundel County. 



Collections. Maryland Geological Survey, Philadelphia Academy of 

 Natural Sciences, New Jersey Geological Survey. 



Outside Distribution. Matawan Formation. Marshalltown clay marl, 

 Wenonah sand, New Jersey. Monmouth Formation. ? Navesink marl, 

 ? Eed Bank sand, ? Tinton beds, New Jersey. 



CRASSATELLITES LINTEUS (Conrad) Johnson 

 Plate XXXIX, Figs. 6, 7 



Crassatella lintea Conrad, 1860, Jour. Acad. Nat. Sci., Phila., 2d ser., vol. 

 iv, p. 279, pi. xlvi, fig. 5. 



Crassatella lintea Meek, 1864, Check List Inv. Fossils, North America, 

 Cret. and Jur., p. 11. 



Crassatella lintea Conrad, 1868, Cook's Geol. of New Jersey, p. 726. 



Crassatellites linteus Johnson, 1905, Proc. Acad. Nat. Sci., Phila., p. 14. 



Crassatellites subplanus Weller, 1907, Geol. Survey of New Jersey, Pal., 

 vol. iv, p. 553, pi. Ixi, figs. 3, 4 (ex parte, synonymy and figs. 1, 2 ex- 

 cluded.) 



Description. " Subovate or subtriangular, convex, inequilateral ; disk 

 concentrically ridged and finally striated, slightly contracted near the 

 umbonal slope, which is rounded; posterior extremity subtruncated ; apex 

 slightly prominent; posterior dorsal line nearly straight, very oblique; 

 margin within finely crenulated; lunule long and lanceolate." Conrad, 

 1860. 



Type Locality. Alabama. 



