78 



whirl by any profound depression, and not prominent; labrum 

 within lineated with elevated, abbreviated or interrupted lines, not 

 incrassated, purple-black ; columella at base with a prominence or 

 fold. 



Length three-fifths of an inch. Inhabits the coast of the United 

 States. Cabinet of the Academy and Philadelphia Museum. 



Animal. — Foot as long as] the shell, rounded before, with the 

 anterior angles elongated, conic, reflected and resembling short 

 tentacula ; head not extended beyond the shell ; eyes above the 

 base of the tentacula, placed on the exterior side and black ; tenta- 

 cula setaceous, abruptly smaller above the eyes ; trunk cylindrical, 

 the suture beneath exserted over the head, half as long as the 

 shell and veiy conspicuous. 



Inhabits the shores of our estuaries in great numbers. When 

 left by the recess of the tide, they collect together in small pools, 

 or crawl in pursuit of the retiring water ; but when left quite dry, 

 they biuTow in the sand so as to conceal themselves from the action 

 of the sun, and patiently await the returning tide. They assemble 

 about dead crabs and other animals, and aj^pear to feed upon them. 



This shell is more frequented by Pagurus longicarjms than any 

 other ', it bears a general resemblance to the preceding species, but 

 is sufficiently distinguished by being less elongated, the suture and 

 impressed lines not being so profound and the beak less prominent 

 and distinct ; the color is also very different. 



It resembles the shell represented by Lister, plate 276, fig. 32. 

 " Buccinum B. r. parvum nigrum ex toto laeve." It is usually 

 covered by a blackish pigment which obscures its character : 

 within the aperture, on many specimens, a dull or obsolete whitish 

 line may be seen. 



The description shows the near approach of this shell to Mont- 

 fort's genus jP/<o.s, to which it is as closely allied as the preceding 

 species. 



Nassa acuta. — Shell conic acute, whitish, cancellated so as to 

 appear gi-anulated, granules prominent, somewhat transverse, ine- 

 quidistant, the transverse grooves being more profound and dilated 

 than the spiral ones, which are six in number ; spire longer than 

 the body whirl, slender towards the tip, acute ; suture impressed, 

 but not profoundly ; beak distinguished by a depression from the 



