LAMELLIBKAXCHIATA OF THE LOWER MAELS. 105 



feel some doubt in regard to its correct identification from New Jersey 

 without personal inspection. Some of the shorter specimens of N. Slackiana 

 Gabb agree nearly with the above description, but I have preferred to 

 adopt the name which is accompanied with a figure rather than one without, 

 where there is so much uncertaintv as in this case. 



Genus XUCULANA Link. 

 Nuculana protexta. 

 Plate XI, Fig. 10. 



Leda protexta Gabb. J. A. ]!i^. Sci., Phil., new ser., Vol. IT, p. 303, PL XLYIII, Fig. 



23 on Plate XXIII in text. 

 Nnculana protexta Gabb. Proc. A. X. Sci., 1876, p. 318. ^Nleek, Geol. Kept. X. J., 



1868, p. 725. 

 Xot Leda protexta Gabb. J. A. X. Sci., Phil., Vol. IV, PL LXVIII, Fig. 36, p. 397. 

 Xot Yoldia protexta Conrad=r. albaria. Con., Am. Jour. Conch., Vol. I, p. 213, PL 



XXI, Fig. 2, VoL III, p. 8. 



Shell very elongate and narrow, the narrow end about once and a 

 half as Ions: as the wider and stronirlv recurved. Yalves moderatelv ven- 

 tricose and the beaks only moderately elevated; anterior end narrowly 

 rounded and the posterior extremity extended and narrow; basal line 

 gibbous in the middle. On the cast the hinge is seen to be marked by a 

 very large number of small teeth, but the 'number cannot be made out on 

 any of the several specimens examined. The cartilage pit beneath the 

 beak has been of moderate size. Surface features of the shell unknown. 



This species very closely resembles Perrisonofa protexta Conrad, sp., 

 and would probably also fall under that genus if retained. It differs in 

 being a little less elongated posteriorly, while the anterior or larger end is 

 proportionally very much more elongated, throwing the beaks more nearly 

 in the middle of the length of the shell. The posterior cardinal slope is 

 not flattened and distinctly separated from the body of the shell by an in- 

 distinct ridge as in that species. There has been considerable confusion in 

 regard to the use of the specific name protexta in this group of shells, as it 

 has been applied to three distinct species at different times. Two of them 

 criven by Mr. Gabb and one bv Mr. Conrad. I have retained it for this 



to ..' 



species as it is the earliest application of the name. Mr. Conrad changed 



