ORDER DECAPODA. 
169 
In his Libinia , properly so called, the claws of the males 
are thicker than the two following feet, and almost as long ; 
the length of those which are the longest is not altogether 
double that of the testa. ( Libinia canaliculata , Say. emar- 
ginata , Leach.) 
The claws of the males of Docl&a are notably shorter than 
the two following feet ; the length of these feet scarcely ex- 
ceeds more than once and a half that of the testa, which is 
almost globular, and always covered with a brown or blackish 
down. ( Doclcea Rissonii, Leach.) 
In Egeria the claws are filiform, with the hands very much 
elongated, and almost linear. The following feet are five or 
six times longer than the testa. The body is triangular. 
(. Egeria Indie a, Leach.) 
Alter having reviewed the subgenera of this tribe, whose feet 
coming after the claws are of an identical form, and whose tail 
is composed, in the females at least, and most frequently in 
both sexes, ol seven articulations or complete segments, we 
shall pass to those in which it presents but six at most. The 
feet are generally long and filiform, as in the last subgenera. 
If we except leptopus , these Crustacea are again remote from 
the preceding, in the relation of the form of the third articu- 
lation of the external jaw-feet ; it is proportionally more nar- 
row, contracted at its base, and the following articulation 
appears to be inserted at the middle of its upper edge, or 
more externally. Ihe following subgenus differs from those 
which succeed it, by having but three segments in the tail 
of the males. The form of the third articulation of the ex- 
ternal jaw-feet appears to me to be in other respects the 
same as in the preceding subgenera. 
Leptopus, Lam. 
1 ho tail of the females is formed of five segments. The 
