60 PALfiONTOUXlY OF NEW JEKSEV. 



Family CRASSATKI.I.ID^E. - 

 (i^enus CRASSATEFJiA Tjiiiiiaix^k. 



ORASSATELI.A MELINA. 



Plate viit, tis'.-i. ll-l.i. 



Cmssatdla mclina Conrad; Foss. Shells of tlie Tert. Form. N. A., j). 23, PI. ix, fig. 2; 

 Medial Tert. Form., p. 22, PI. xii, i\g. 2; Meek, Smith. Check List, p. 7. 



]\rr. Conriid (Icscrilx's tliis sliell originally from ('unibcrland County, 

 N. J., as follows: "Shell subovate, convex-depresstHl; uniboiies with a few 

 reg'ulai' ratiier wide sulci; umboual slope nearly rectilinear, ang>ular; dorsal 

 margin very sliohtly concave; extremity obliquely truncated; anterior mar- 

 gin reg'ularh' rounded." In his observations he says it diti'ers from C. undu- 

 lata in being proportionally much shorter, and more widelv truncated at 

 the extremity, while the dorsal margin is less concave; and from tlu^ C. 

 Marylandicd in "being thinner and more compressed." 



The shell^, as I find them, are broadly subovate, nmch the widest ante- 

 riorly, Avith the apex of the valves at about two-fifths of the entire length 

 from the anterior end. T\w ])osterior cardinal margin slopes rapidl)', and 

 with but little concavity, from the beak to the posterior end which is usually 

 about half as high as the .shell from the 1ieak to the basal margin opposite. 

 The l)ody of the shell is rather convex, especiallv in old thickened speci- 

 mens. The umbonal ridge is somewhat angular and the posterior umboual 

 .slope rather abrupt. Mr. Conrad states that it is thinner than C. Mari/lmi(Jira. 

 If l)y this is understood the thickness or weight of the sliell, some of the 

 sjjecimens before me would not bear out the observation, as they are greatly 

 thickened, and in comparison to the size of the shell would appear to be 

 heavier than any individuals of that species I have noticed. Or if he 

 refeiTed to the general con\exity of the valves, many of them are very 

 rotund; although the majority are perhaps rather depi-essed convex, llie 

 hinge of the shell is very strong, and usually quite wide, but the teeth are 

 comparatively thin and slender,, while the ligamental pit is bi'oad and well 

 defined. The nuiscular im[)rints are large and deejjly marked. A pecidiar 

 feature noticeable among the shells is a tendencv of the surface to exfoliate 



