BRITISH STALK-EYED CRUSTACEA. 363 
Pisa Gibbsit was, according to Dr. Leach, discovered by Gibbs, 
who was employed as a collector by Colonel Montagu. It is 
apparently not rare on the south coast in depths of from five to 
twenty fathoms, and has been recorded from Devon, Cornwall, 
Brighton, and Hastings. Prof. Milne-Kdwards gives its localities 
as the shores of France and England. We have obtained it 
principally from mid-channel, whence it was obtained by dredging. 
We also obtained some from the Channel Islands, amongst which 
were two beautiful varieties, both males, the colour of which 
was a rich carmine, the brightness of which did not entirely 
disappear at death. 
The usual colour of this species is a russet-brown, varying 
occasionally in shade. It is stated to be with ova in December. 
The following is a short description of six specimens of Pisa 
Gibbsii in Mr. Carrington’s cabinet :— 
No. 1.—This specimen is figured at p. 361, and is covered 
with a rounded growth of the sponge Dysidea fragilis. This 
sponge had almost completely enveloped the animal, and illus- 
trates our previous observation as to the ultimate destruction 
of the enclosed crustacean, as there is every probability that 
this identical specimen would have at length become help- 
lessly covered by the external growth. This sponge is extremely 
brittle when dry, and comparatively so when living, being com- 
posed to a large extent of sand. 
No. 2.—This specimen, also figured at p. 361, is the most 
beautiful of the series. It carries on its carapace a rare 
sponge, Isodictya, which is attached by its base across the 
carapace from one side to the other, as shown in the figure. It 
rises to a height of about an inch and a half, and is about half an 
inch thick. Its colour is a most delicate glossy white, and when 
the crab reached us alive, with its burden in a fresh condition, it 
was a most lovely object, the contrast of colour having a most 
striking effect. 
No. 8.—This specimen carries a large sponge, Desmacidon 
rotalis, which is one of our rare forms. This sponge is massive, 
sessile, and uneven or ragged, and of a dark warm-brown colour; 
it completely covers the upper carapace, and rises to a height 
of an inch and a half from its base. The eye-stalks of the crab 
are free, as their motion prevents the growth of the sponge upon 
them. 
