270 INVERTEBRATA OF MASSACHUSETTS. 



Odostumia produ'cta. 



Shell small, conic-cylindricnl ; ivhorls eight, ncarhj fiat ; epi- 

 dermis light-hroivn ; columella fiexuous. 



Figure 175. 



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



Jaminia producia, 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 lip around it, so as to produce a partial fold. 

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

 side. Length -J: inch, breadth j^ inch, divergence 12'-^. 



Found by Professor Adams, in September, 1S39, 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 veiy 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. j)rod{icta is not 

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

 very much more slender and cylindrical foi-m; 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-urnbil- 

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



Figure 176. 



