164 
CLASS CRUSTACEA. 
upon themselves, with the fingers abruptly bent, and forming 
an angle ; ocular pedicles very short, and not at all, or very 
little projecting from their cavities, and a shelly testa, very 
unequal, or very spiny, characterize 
Parthenope, Fab. 
Some of them have the lateral antennae very short, of the 
length of the eyes at most. Their first articulation is entirely 
situated below the ocular cavities. 
If the tail presents in both sexes seven segments, these spe- 
cies will compose Parthenope, properly so called, of Dr. 
Leach. If those of the males present but five, we shall have 
his genus Lambrus . 
The others have the lateral antennae very sensibly longer 
than the eyes. Their first articulation is prolonged as far as 
the internal upper extremity of the cavities proper to these 
last organs, and appears to be confounded with the testa. 
Here the post-abdomen always consists of seven segments. 
The claws of the females are much shorter than those of the 
other sex. The same naturalist distinguishes generically 
these Crustacea under tlie denomination of Eurynoma. (Can- 
cer asper Pennant.) 
In the following the claws are always advanced, and their 
length is at most double that of the body. Their fingers are 
not abruptly and angularly inclined. 
Here the length of the longest feet (the second pair) little ex- 
ceeds that of the testa, measured from the eyes to the origin of 
the tail. The under part of the tarsi is generally either den- 
ticulated or spiny, or garnished with a fringe of hairs, termi- 
nating like a knob. 
We shall present, in the first place, those whose ocular 
pedicles are very short, and of middle length, capable of 
