ge 
E 
164 Couthouy’s Monograph on 
£ 
circle. M. de Blainville characterizes it as transverse, 
which gives at best a very imperfect idea of its structure. 
In fact, judging from his description and that of M. 
Rang, unassisted by figures, a person with the very shell 
in question before him, might well be excused for con- 
sidering it distinct, or at'all events hesitating in his de- 
cision. Since many in this country, are from lack of the 
`i means of comparison, likely to be thus confused, and as 
= 
M. Deshayes, in his receht edition of Lamarck, has not 
corrected the error relative to the valves, merely stating 
them to be dissimilar, nor spoken of the unusual position 
of the external ligament, T have thought these points of 
sufficient importance to demand a new and more accu- 
rate characterization of the genus, which accordingly I 
have endeavored here to give. It should also be ob- 
served, that the division B, of M. de Blainville and M. 
Rang, founded on Awnarina rupicola; Lam., 
RuricoLa, Fleur. de Bellevue, should. be $ supprésse 
that shell having since been ascertained tol ek ng. 
e perforating Corbule. The generic synomo 
also, for reasons peed specified, shoul des 
out. 
ever having been given, it was thought advis: 
sent the detailed one preceding these remar : 
There is still one point of difference between - 
Deshayes and M. de Blainville, in. relation to this on 
cies, which cannot be cleared up: on this side of the 
water. - The former, in his continuation of Lamarck, 
“VI. p. 16, 11, remarks that “ in the Anatina trapezoides, 
eS v nC(— a Corba a, and on which M. 
* 
ae of the Poncii ¢ statements yespectisi e 
this shell, and, as is believed, no full descriptido of it ; 
