229 
nitiday Poll, but tbe beaks are rather more anterior. The anterior 
side is a little more obtuse than that of T. pulcliella, Lam.^ and a 
little more curved to the left nearer the tip. It evidently resem- 
bles T. depressa, Gmelin, but I cannot perceive any lateral tooth. 
PI. 65, fig. 3. 
Tellina tenuis, Da Costa . — Specific character. Shell oval" 
triangular, irregularly striate concentrically; each valve with two 
teeth, and one of them with lateral teeth. ”1" '^7. 
Tellina tenuis. Da Costa, Brit. Conch., p. 210. Chem. 6, p ^ 
124, tab. 12, fig. 117. Donavan, i. tab. 19, three lower figures. 
Penn. Brit. Zool.^.p. 180, tab. b\,fig. 2. Mont. Test. Brit,, p. 
59. Turton, Brit. Fauna, p. 150, Wood, Conch, p. 155, tab. 44,, 
figs. 3 and 4. Conch. Diet., p. 169. Conch. Ins. Brit.,p. 107. 
T. levis. List. Conch., t. 405, 251. 
Obs. There may frequently be observed some very minute and 
fine longitudinal white lines, from which circumstance it has been 
often mistaken for T. striata ; but the lateral teeth will at all 
times distinguish it, there being two small lateral teeth in one of 
the valves only. We believe that the T. balaustina and T. planata 
of Linnmus are among the numerous varieties of this species.— 
(Turton.) 
I have copied the above from Turton’s “ Bivalves of the British 
Islands,^^ believing our shell to be the tenuis of authors. Mr. Say, 
unfortunately, has left no description of this species, which was 
sent to him by Professor Bavenel of Charleston, who found it on 
the shore of Sullivan’s Island. — -Ed.* PI. 64, fig. 3. 
Arca zebra, Swain . — Specific character. Margins angulated ; 
valves marked with simple uniform and regular grooves, radiating 
from the umbones ; shell transversely and obliquely striped with 
brown. 
Arca zebra, Swainson. Zool.lllus., No. 2d, pi. 118. 
Obs. Inhabits the coast of the peninsular of Florida. 
Mr. Swainson has separated this species from the Arca no^ of 
authors, and refers it to his subgenus Byssoarca. He observes : 
The animals of these shells afi&x themselves to other bodies by a 
particular muscle, which is protruded through the gaping part of 
the valves ; they also adhere, when young, by the byssiform epi- 
*[T, A. Conrad.] 
