270 INVERTEBRATA OF MASSACHUSETTS. 



Odostomia produ'cta. 



Shell small, conic-cylindrical; whorls eight, nearly fiat ; epi- 

 dermis light-brown ; columella fiexuous. 



Figure 175. 



State Coll., No. 28. Soc. Cab., No. 2372. 



Jaminia producta, Adams ; Bost. Journ. J^at. Hist., iii. pi. 3, f. 8. 



Shell small, elongated, conic-cylindrical, very slender, com- 

 posed of eight or more flattish whorls, separated by a well-im- 

 pressed suture ; tip blunted, as if one or more whorls were re- 

 moved ; surface faintly marked by lines of growth, and covered 

 with a dusky, horn-colored epidermis ; occasionally, an indistinct 

 revolving line may be seen on two or three of the lowest whorls ; 

 aperture about one fourth the length of the shell, ovate, regularly 

 rounded in front, the pillar margin modified by the rising and re- 

 volving of the outer hp around it, so as to produce a partial fold. 

 Umbilicus none. Operculum thin, horny, spiral, apex at one 

 side. Length I inch, breadth y'^ inch, divergence 12°. 



Found by Professor Adams, in September, 1839, near- high- 

 water mark, in a cove on the east side of Fairhaven. 



It is distinguished from O. exigua by the same characters as 

 O.fusca is. To this last it is very closely allied; and, as neither of 

 them has any very prominent peculiarities, it may not be possible to 

 make apparent in words, distinctions which are quite obvious to the 

 eye. This is, however, a much more slender shell than O.fusca, has 

 one or more additional whorls, a much lighter colored epidermis, less 

 convex whorls, and no approach to an umbilicus. While the two 

 shells are about equal in length, the lower whorl of O. producta is not 

 more than two thirds as large as that of O. fusca ; so that it has a 

 very much more slender and cylindrical form ; and this it is, which 

 most readily strikes the eye on comparison. 



This does not belong to the genus Jami'nia of Leach ; and Brown 

 has given us no characters for the genus, as he employs it. 



Odostomia fusca. 



Shell small, elevated-conical, rather blunt at tip, and sub-umbil- 

 icated ; color darli-brown ; aperture broadly -ovate. 



Figure 176. 



