TURBINACEA. MOLLUSCA. TURRITELLA. 267 



GENUS TURRIT&LLA, LAM. 



Shell turreted, elongated, spirally grooved, pointed; aperture 

 entire, rounded; lips disjoined posteriorly ; operculum horny. 



TURRITE'LLA EROSA. 



Shell elongate-turreted , pale-brown, composed of about ten 

 smooth, flattish whorls, sloping above to the suture^ and grooved 

 with from three to five, obtuse, revolving furroivs. 



State Coll., No. 38. Soc. Cab., No. 2286. 



Turritella erosa, COUTHOUY j Bost. Journ. Jfat. Hist., ii. 103, pi. 3, f. 1. 



Shell elongated-conical, turreted, pale horn-colored, with a 

 light reddish-brown epidermis ; whorls about ten, flattish, smooth, 

 sloping towards the suture, so that each whorl seems a little shelv- 

 ing over the succeeding one, and furrowed with from three to 

 five abrupt, revolving grooves, nearly as wide as the spaces be- 

 tween them. From five on the largest whorl, the number goes 

 on diminishing above ; the whorls at the apex are usually broken 

 off, and much of the summit is a good deal eroded. Lines of 

 growth are quite conspicuous in the grooves, but scarcely percep- 

 tible elsewhere ; aperture nearly circular ; lip sharp, meeting the 

 prolonged pillar, so as to produce a partial angle ; operculum 

 horny, multi-spiral. Length inch, breadth -f- inch. 



Found in the stomachs of fishes caught in Massachusetts Bay. 

 It is usually found either incomplete, or much defaced and 

 broken. I have seen but one specimen containing the animal. 



It is quite different from any described species, unless it be T. Vir- 

 ginidna of Lamarck. His description is not sufficiently definite to 

 identify his shell with ours, and the character " basi annulo griseo-viola- 

 cescente notata," I have never found upon it. It bears a distant re- 

 semblance to the old Turbo terebra of English authors, but it does not 

 slope to a point so rapidly, and the sculpture seems to be from grooves, 

 and not from raised lines, as in T. terebra. 



