Fam. 12.] NATURAL HISTORY SOCIETY. ^5 



1. Turtonia minuta, Fabr. Shell very minute, fragile, semi- 

 transparent, elongated-ovate, rather convex ; posterior end nar- 

 row and somewhat pointed ; umbones slightly elevated 5 lower 

 margin well curved. Straw color, blending into dark purple at 

 the umbones and posterior slope; interior similar. L. 2 ; H. IJ; 

 W. 1 ; U. J. — New England, Common under stones at low 

 water. 



2. Kellia, Tur. 



Shell small, thin, suborbicular, closed; umbones small; mar- 

 gin smooth ; ligament semi-internal ; cardinal teeth, 1 or 2 in 

 €ach valve. 



Animal with incurrent opening in front, and excurrent be- 

 hind ; foot strap-shaped, and with a byssus groove. 



1. Kellia plamdato., Stim. Shell minute, closed, not very thin, 

 oval-oblong, ends broadly rounded ; umbones a little prominent, 

 and in contact; lunule elongated, smooth, deep; surface marked 

 with lines of growth, eroded at the umbones; muscular impres- 

 sions and pailial line faint. White, covered with a rather thick, 

 dirty-brown epidermis ; inside white and glossy. L. 4 ; H. 3 ; 

 W. 1|; U. J. — New England. Under stones at low water; rather 

 rare. 



Family 12. UNGULINID/E. 



Shells rounded, small, thin, with slender cardinal teeth or none; 

 ligament partially or wholly internal. 



* Shell minute, elongated, without gonial folds..... 1. Tellimya. 



* Shell globular, with gonial groove 2, Cryptodon. 



1. Tellimya, Br. 



Shell minute, thin, oblong; umbones back of the centre; 

 hinge line notched ; cartilage internal, between two, thin teeth 

 in each valve. 



Animal with a single, siphonal orifice ; foot large, broad, and 

 with a byssus groove. 



1. Tellimya elevata, Stim. Shell fragile, slightly gaping, ovate- 

 oblong, both ends obtusely rounded, the front end broader, 

 tumid near the umbones, but compressed near the margins; 

 umbones acute and prominent; surface shining, but rough with 

 the numerous edges of the lines of growth ; inside polished, 

 without apparent muscular or pailial impressions, except in 

 very old shells, but with faintly marked, radiating lines ; carti- 



