50 MR. T. BELL ON THE CRUSTACEA 
Genus Pisa, Leach. 
Pisa SPINIPES. 
Tab. IX. Fig. 6. 
Pisa testd ovatd ; dente articuli basilaris antenne exterioris dente superorbitali longiore ; 
margine antico-laterali et pedibus omnibus spinosis. 
Hab. ad Insulas Gallapagos dictas, et apud Sanctam Elenam. 
$ Mus. Soc. Zool.— ? Mus. Bell. 
This is an elegant little species, bearing considerable resemblance to young specimens 
of Pisa tetraodon, Leach, but differing in many essential particulars from this and 
every other known species. 
The carapax is depressed and granulated: the lateral margin on each side beset with 
about seven or eight sharp spines, which are much smaller and shorter in the female 
than in the male. The former sex has a strongly-marked granulated line over the pos- 
terior margin, which is much less conspicuous in the male; a circumstance which I 
have observed in many species, not only of this but of several other genera. The tooth 
above the orbit, unlike many other species, is shorter than that of the basilar joint of 
the exterior antenne. The horns of the rostrum are separated throughout their length, 
and are somewhat divergent. 
The abdomen of the male specimen was lost: that of the female is as broad as it is 
long, and has a low longitudinal carina. 
The feet are all furnished with small spines, particularly on the third joint ; the ante- 
rior pair in the female scarcely larger than the rest: those of the male specimen were 
lost. 
This species differs from all the others, excepting Pisa Styx, Latr., in having numer- 
ous spines on the legs. 
Length 8 lines ; breadth 5 lines. 
The male specimen was taken by Mr. Cuming at the Gallapagos, at the depth of 
sixteen fathoms ; the female at St. Elena at six fathoms: both on sandy mud. 
Pisa ACULEATA. 
Tab. IX. Fig. 7. 
Pisa testé triangulari, dente articuli basilaris antenne exterioris dente superorbitali breviore ; 
margine antico-laterali inermi, regione branchiali spinis quatuor armatd ; pedibus supra 
spinosis. 
Hab. ad Insulas Gallapagos dictas. 
Mus. Soc. Zool., Bell. 
Carapax triangular, nearly as broad as it is long: the latero-anterior margin without 
