296 TELLINID^. 



striolate concentrically, the striuliTe being remarkaLly close 

 set ; the ventral margin is convex, but not quite symme- 

 trical, the anterior portion being the more arcuated ; the 

 front dorsal outline is nearly straight, produced, and scarce- 

 ly at all sloping, the hinder is extremely short and mode- 

 rately declining ; both extremities are rounded, but neither 

 symmetrically, that is to say, with an equal arcuation 

 above and below, the extremely blunt subangulation of the 

 posterior termination forbidding it behind, and the slight- 

 ness of the front dorsal slope preventing it in front ; this 

 character, however, is not so peculiarly evident as in Dona- 

 cma ; the sides are excessively unequal, the front being 

 twice or even thrice the length of the hinder ; the liga- 

 ment is prominent, but very short, the ventral flexure 

 distinct, but the umbonal fold almost obsolete ; there is 

 a linear, lunule-like excavation along the front dorsal edge, 

 which is only at times stained with reddish crimson inter- 

 nally ; besides the narrow, simple, and small bifid tooth 

 of each valve, the right possesses a large anterior and a 

 small posterior lateral tooth, which are moderate!}^ and 

 equally distant from the former. Although most closely 

 bordering upon T. donacina, this beautiful and diminutive 

 species appears to us specifically distinct, and not merely, 

 as has been conjectured by some, a dwarf variety of that 

 long-known shell. It does not seem, indeed, to have been 

 found at all by the older conchologists, with the exception 

 of Mr. Humphreys of Cork, in whose cabinet it is still 

 preserved ; so that whether the sum of its difi^erence from 

 its nearest congener be vai-ied or specific has not yet been 

 mooted among us. In his interesting Prodromus of the 

 shells of Sweden, Loven has lately constituted it a species, 

 and to his opinion we assent, in common with those other 

 British conchologists who have devoted their attention to 



