180 
CRUSTACEA. 
leng'tli of the eyes; the first joint is entirely situated under the oculai 
cavities. 
If there are seven segments in the tail of both sexes, we have the 
genus Parthenope properly so called * * * § of Leach. 
If that of the males presents hut five, it is his genus Lamhrus t- 
The lateral antennae of the others are sensibly longer than the eyes ; 
their first joint extends to the superior internal extremity of the 
cavities peculiar to tliese latter organs, and ai)pears to be confound- 
ed A^’ith the shell. The post-abdomen is always composed of seven 
segments. The claws of the females are much shorter than those of 
tlie opposite sex. The same naturalist distinguishes these Crustacea 
generically by the name of Eurynoma. But a single species is known 
which inhabits the English and French coasts ;}:. 
All the other Parthenopes, one excepted §, are from the Indian 
Ocean. 
In the following ones, the claws always pi'oject, and their length, at 
most, is double that of the body ; their fingers are not suddenly bent 
into an angle ||. 
Here the length of the longest feet — the second — barely exceeds 
that of the shell from the eyes to the origin of the tail. The under 
part of the tarsi is usually either dentated or spiny, or furnished avith 
a ciliated fringe terminated like a club. 
We Avill commence avith those whose oevdar pedicles are A'ery short, 
or of a mean length, susceptible of being entirely retracted within 
their cavities, a-nd avhose claws, at least in the males, are considerably 
thicker than the other feet. 
Mithrax, Leach. 
Robust claws ; ends of the fingers like the bowl of a spoon ; stem 
of the lateral autennee sensibly shorter than the pedicle ; the tail 
composed of seven segments in both sexes. 
All the known species are from the American seas^. 
Acantkonyx, Latr. 
A tootii or spiniform projection on the inferior side of the tibise ; 
under part of the tarsi pilose, and as if pectinated ; superior surface 
* Parthen. horrida, Fah.; Riunpli., Mus., IX, 1 ; Seba, III, xix, lo, 17 ; Herbst , 
XIV, 88. 
-|' Fanth. lonyimana, Fab.; Rumpb., Mus., YIII ; — P.giraffa, Fab.; Herbst., 
XIX, 108, 109; — P. htr, Fab. ; — P. ruhus, Latr. ; — Cancer contrarius, Herbst., lx, 
3; — P. macrocheles, Lat., Herbst., XIX, 107 ; — ('oncer longiinanus, L., fein., P. 
irigonomana, Lat.; Cancer prensor, Herbst., xli, 3. 
Cancer asper, Penn., Brit. Zool., lY ; Eurynoma aspera, Leach, Malac. Brit., 
XYII. 
§ Parihenope angvH/rons, Latr., Encyc. Method. ; Cancer longimanus, OUvi. 
II The first joint of the lateral antenna; appearing to form part of the shell, has 
been mistaken by several naturalists, the second having been considered by them 
as the first. 
•(i Mithrax spinicinctus, Latr.; Desmar., Consid., p. 150; — Cancer, hispidvs, 
Herbst., XYIII, 100 ; — Cancer aculcatus, Herbst., XIX, 104 ; — C. spmipes, ejusd., 
XYII, 94. The laclms hircus, Fab., is perhaps a congener. 
