358 THE ZOOLOGIST. 
NOTES AND OBSERVATIONS ON BRITISH 
STALK-EYED CRUSTACEA. 
By Jonn T. Carrineton, F.L.S., anp Epwarp Lover. 
(Continued from p. 307.) 
Genus Pisa, Leach. 
Perhaps no other genus of the British Podopthalmia is of such 
interest, or presents such remarkable features in its life-history, 
as the genus Pisa. It comprises two very characteristic species 
hitherto known from our seas, but is more fully represented in 
warmer latitudes, where, in all probability, numbers of still 
undescribed species exist. In the Adriatic Sea alone, according 
to Prof. Luigi Stalio,* six species are described. 
The general form of the carapace of Pisa is triangular, the 
anterior angle being finished by a stout bifid rostrum, varying 
slightly in the two species. Its appearance is spinous, and the 
legs are shorter in comparison with the body than those of the 
other “Spider Crabs.” The antenne are about as long as the 
rostrum, the second joint being slender. The external pedipalps 
are broad, and the abdomen is seven-jointed in both sexes. As 
the specific characteristics are, although so closely allied, yet so 
distinct, it is perhaps more advantageous to simply sketch the 
generic features rather than to attempt details which are subject 
to variation. For instance, the club-shaped hairs of the antenne 
alluded to by Bell can scarcely be said to refer equally to 
both species, seeing that the general covering of the carapace is 
so extremely dissimilar in the two; and, in fact, his two figures+ 
represent antenne of considerably different structure as to this 
hairy covering. 
Pisa tetraodon, Leach. 
The carapace of this species is about an inch and a half long 
in the adult, although specimens occasionally occur in which this 
length is exceeded. ‘The greatest breadth is about an inch. 
Although roughly triangular, its form is much more rounded than 
* ‘Atti del Reale Instituto Veneto,’ Tom. iii., ser. 5, p. 375. 
+ ‘British Stalk-eyed Crustacea,’ pp. 22 and 27. 
