the Family Osteodesmacea. | 167 
(oe the term “ cuilleron") are. very 
closely, along the posterior cardinal edge, which is a 
little depressed or indented in that portion. They are 
not exactly parallel, but diverge a little from the beaks 
toward the posterior extremity. In conformity with this 
divergence, the ossiculum which covers them, instead of 
being, as in all the rest of the family, at one of the 
extremities, is jgregalarly oblong, and im some cases 
almost cuneiform, the » narrower end being next the . 
`+ beaks. M. Deshayes observes, that Lamarck’s Mya 
a solemydl [ the shores of New Holland, is an un- 
doubted Osteodésma. 
As this genus is very little known to American natu- 
Xilists generally, in. consequence: of its erroneous sup- 
| pression. as identical with eon by M. de Blain- 
and : Rang in 
d. 
ared the more PEE pe. a though 
dn. his article ee Encyc. Meth. 
s, HE p. 7 139, in noticing the mis stake of M. de Blain- 
] yen us to his article: on OsrsópEsA for its ac- 
yet, by a singular oversight, that article 
Consequent Ys. s idi only work in 
is his recent 
e are probably but 
uniry. 
shores, has been ded 
the earl r! Pwriters d 
rbuloides, Lam. Mis ° 
cata d 
