228 PALEONTOLOGY OF NEW JERSEY. 



now. If 110 distortion has taken place, the form would be quite different 

 from any known species. In size it corresponds to N. Slackiana Gabb, from 

 the Lower Marls, and also to N. magnifica Conrad, from the Eocene sands of 

 Claiborne, Ala., but in its proportions of form it differs from either very 

 materially. 



Formation and locality. — In the upj^er layers of the Upper Marls, at 

 Shark River, New Jersey. 



Genus NUCULANA Morcb. 



Nnculaua albaria. 

 Plate XXIX, Figs. 15 aud IG. 



YoUia protexta Courad. Am. Jour. Couch., Vol. I, p. 213, PI. XXI, Fig. 2. Meek, 



Geol. Surv. N. J., 1SC8, p. 731. Courad, Check list. Eocene Foss., p. 4. 

 Y. albaria Conrad. Am. Jour. Couch., Vol. Ill, p. 8. 

 Not Toldia protexta Gabb. 



Shell of medium size, transversely elongate-ellijatical, varying- from 

 considerably less to a little more than twice as long as high, and the oppo- 

 site ends of the shell nearly or quite of equal length, although differing 

 materially in height. Narrow end of the shell recurved and obtusely 

 pointed; opposite extremity more broadly rounded; base nearly equally 

 curved throughout. Beaks small and appressed. Hinge-line marked b}^ 

 about twenty somewliat curved teeth on the broad side of the shell, and by 

 twenty-three or twenty-five on the pointed end; ligamental pit of consider- 

 able size. Surface of the shell marked by very fine even striae of growth. 



Mr. Conrad first described this shell under the name Yoldia protexia^ but 

 subsequently changed it to Y. albaria on ascertaining that Mr. Gabb had 

 already used that name for a Cretaceous species. The casts very closely re- 

 semble those of Y. jtrofexfa Gabb, so much so that it is difficult to point out 

 differences. The shell is, however, more equilateral and appears to have been 

 a trifle higher and to have been less recurved at the narrow end; otherwise 

 they are strikingly similar. Mr. Conrad's figure in the American Journal of 

 Conchology is very poor, and represents the narrow end of the shell as much 

 longer in proportion to the other than in any specimen which has come 

 under my observation. He also describes it as "anterior side longest." I 



