324 PROCEEDINGS OF THE ACADEMY OF 



One specimen in my collection, from Burlington Co., N. J. 



Total length of tube about 1.75 in. Greatest diameter *5 in. Length of 

 shell about -25 in. Width about 3 in. 



The surface markings are about exactly like those of Xylophaga Stimpsonii 

 M. & H., but the beaks are more prominent and the crenulations along the 

 vertical furrow, extending from the beak, are much finer and more numerous. 

 It is less oval in form than Pholas (Xylophaga) elegantula M. & H. The gaping 

 appearance of the posterior end may be due to the peculiar position of the 

 shell in the matrix. If it should prove to be closed, the species will belong to 

 the genus Xylophaga. 



Pholas Linn. 



P. cretacea? Gabb. Jour. Acad. 2d s. vol. 4, p. 393, pi. 68, f. 18. 



Shell broadly cuneate, beaks very much incurved. Umbones broad ; buccal 

 extremity rather abrupt, convex. Cardinal margin rounded, sloping down- 

 wards towards the anal end, which is rather broad. Basal margin nearly 

 straight, perhaps a little emarginate. Surface marked by a deep groove ex- 

 tending a little obliquely backwards from the beaks to the basal edge. In 

 advance of this are curved striae, very distinct and parallel, or nearly so, with 

 the margin, which, immediately on crossing the groove, become straight. 

 From a very small fragment of the shells attached to the cast, we find that 

 between these grooves are small sharp ridges. 



Length -21 in. Width -32 in. Diameter -2 in. 



This small shell, of which I have seen but one specimen, is referred pro- 

 visionally to the above species, described only from the tubes, because it is 

 of about the proper size to form such tubes, is found in the same deposit, and 

 is the only species known in the New Jersey deposits, except P. cithara Morton, 

 which is about an inch in length. The specimen is from Burlington county, 

 and is in my collection. It is so injured by pyrites, that I cannot ascertain 

 how far the lines, described above, extend posteriorly. They seem, however, 

 to continue parallel with the edge. The shell is less truncated in advance 

 than P. cithara, the type of which is in the Academy's collection. The figure 

 given by Dr. Morton is scarcely recognizable. In his specimen the posterior 

 extremity is very narrow and the anterior end is very abruptly truncated, and 

 not produced as in the figure. Mr. Conrad*s figure of the same species, under 

 the name of P. pectorosa, in the Journal of the Academy, 2d s. vol. 2, pi. 2, 

 fig. 9, will convey a better idea of the species. 



Anatina Lam. 



A. elliptica. Shell subelliptical, equivalve, nearly equilateral; beaks 

 central, pointing posteriorly, very small, umbones small. Cardinal margin 

 slightly convex. Buccal margin broad, nearly straight and sloping inwards 

 towards the basal edge, which is very broadly rounded, being nearly straight 

 just opposite the beaks. Anal extremity hardly more than half as broad as 

 the buccal, and with the hinge line between it and the beaks, regularly con- 

 cave. There is a broadly rounded ridge extending from the umbones towards 

 the anterior basal margin, gradually becoming obsolete as it approaches the 

 edge. Shell thin, and marked on the surface by small, irregular concentric 

 ridges. 



Length -9 in. (from beaks to basal margin). Width 1*3 in. 



Locality, Mullica Hill, N. J., collected, with a number of other fine speci- 

 mens, by Messrs. Abbott and Kain. 



Venilia Morton. 



V. trigona. Shell very oblique. Beaks very prominent, anterior, almost 

 terminal, incurved, umbones small, umbonal ridge prominent, subangular 

 slightly rounded on the edge, and extending to the extreme posterior basal 

 angle of the shell. Basal margin nearly straight on the posterior half, regu- 



[Oct. 



