By Mr. ANDREWS. 7 
tuberculata, the absence of denticulations being the only charac- 
ters to separate it from that species. As, however, I have observed 
that no reliance can be placed upon such variations, | must con- 
sider that X. rivulosa and X. tuberculata to possess similiar 
characters, and that the latter figured in the appendix to Bell’s 
British Crustacea, p. 359, is a very doubtful species. 
In order that my views might be corroborated, I forwarded a 
specimen to my friend Professor Allman, F.R.S., President of the 
Linnzean Society, who, in the earlier stages of his scientific 
career, had paid much attention to the crustacea of Ireland. The 
object desired that he might form the comparison with the fine 
series of that genus in the British Museum. His examinations 
were most confirmatory—stating in reply, “ Your view, as to the 
probability of Xantho rivulosa and Xantho tuberculata not 
being distinct species, is fully confirmed by comparison with one 
another of the British Museum specimens; your’s is certainly 
the form there labelled Xantho rivulosa, and that so described 
by Bell.” 
The genus Pilwmnus, of which there is but one known British 
species—hirtellus, hairy crab, is much distributed on the western 
and southern coasts. In rocky pools, at the West Blasket Island, 
it is very numerous, and where I obtained beautiful specimens 
of the Cornish sucker—Lepidogaster cornubiensis, and also 
bymaculatus, 
Similarly only one species of the genus Pirvmela is known, 
the denticulata of Leach. This beautiful little species is richly 
variegated, the colours assuming varied tints, in different 
specimens. It is rather rare, taken in deep water, and is an 
exceedingly active crustacean. When placed in a bowl of sea- 
water with other specimens, it voraciously attacked minute 
specimens of Mysis and Hippolyte. 
Carcinus mcenas, the common shore crab, is so well known to 
every shore-paddling urchin, that no remark is necessary, beyond 
the notice that the only fine specimens are obtained in deep 
water with a small trawl. It is found in the deeper soundings 
of the harbours of Dingle, Ventry, and Valentia, and also of 
Smerwick and Brandon. In those localities it is obtained of 
good size, and also the velvet swimming crab, Portunus puber. 
Both, though rejected in Ireland, are considered in France delicate 
