GASTEROPODA 01* 1:HE LOWER GREEN MARLS. 105 



PLEUROTOMID^. 

 Genus SURCULA H. & A. Adams. 



SURCULA STRIGOSA. 



Plate XIII, Fig. 1. 

 Surcula strigosa Gabb : Proc. Acad. Nat. Sci., Phila., 1876, p. 379. 



Shell elongated, turreted, with an elevated spire; the number of volu- 

 tions unknown, there being now in existence only a fragment of a speci- 

 men, consisting of part of the body volution and the next above ; body volu- 

 tion proportionally large as compared with the other, concave on the upper 

 surface and gently convex on the middle portion, the anterior beak and 

 canal being absent; the next volution above the principal one subangular 

 at the upper third of its height and marked by ten or twelve strong, rounded, 

 vertical folds, and also by moderately strong spiral lines; while the body 

 volution has also been marked by the vertical folds, but less strongly than 

 the other, but is closely covered by nearly equal, vertical and spiral lines 

 cancellating the entire surface; one of the latter, at the lower edge of the 

 concave upper surface, and another a short distance below, have been 

 stronger, and those on the lower half of the volution are somewhat alter- 

 nating in size. 



In Mr. Grabb's description of this shell, which I suppose was drawn 

 from the same individual here used, he states that there are "perhaps 

 eight" volutions, and also says it is 3 inches in length. The specimen 

 has probably been mutilated, or has possibly fallen in pieces since the 

 description was made. The specimen bears no label except that of locality, 

 which is Holmdel, as given by Mr. Gabb. He also states that the speci- 

 men was loaned to him by Prof Gr. H. Cook for description, and as this is 

 the only one found from that locality it is most probably the type. The 

 only species having any resemblance, to it are those herein described as 

 Terricula elegans and T. Leda, neither of which can easily be mistaken for 

 it and neither of which would appear to belong to the same genus, and are 

 readily distinguished by the absence of the concave upper surface on the 

 body volution. 



