156 . Couthouy's Monograph on 
It appears that Mr. Conrad was then not aware that 
Dr. Leach had made the shell first named above, the type 
of his genus Thracia, under the name of T. pubéscens, 
which of course would have taken precedence of the 
latter specific name, admitting our shell and .Mr. Pen- 
nant's to be identical. ‘They are, however, distinct; 
and it also appears proper that our species should re- 
ceive another name, as that given it by Mr. Conrad is 
evidently liable to mislead the foreign naturalist, and 
introduce fresh confusion.. Besides having mistaken 
ours for the British shell, Mr. Conrad has given the 
names of three. distinct species as synonyms. He seems 
to have suspected M. de Blainville’s: figure of T. cor- 
buloides, and Mr. Wood's of Mya convéxa, to represent 
the same shell, and then to have confounded these with 
An. myalis, Lamarck, from whom the rest of the syn- 
onymy is taken. Yet how this could be the case is 
not easy to imagine, as on the same plate where Mr. 
Wood gives a figure of M. convéxa, he gives another of 
M. declivis, which has no resemblance to ours, Even 
without reference to the figures, one would suppose 
Lamarck’s comparison,of A. myális to Mya arenaria, 
certainly not applicable to our Thracia, sufficient to 
have induced a doubt of their identity. Mr. Conrad, 
however, is not alone in'supposing ours to be the same 
as one of the European species. In Professor Hitch- 
cock’s catalogue of the Animals and Plants of Massa- 
chusetts, accompanying his Report on the survey of the 
. State, published in 1834, it is noted, p. 95, as An. con- 
véxa, Wood. Subsequently, on the appearance of Kie- 
ner’s Iconography of recent shells, after an examina- 
tion of his figures, it was decided to be identical with - 
