360 THE ZOOLOGIST. 
The colour of P. tetraodon varies considerably, some that we 
obtained from the Sussex coast being of a dirty brown and liable 
to obscuration by the growth of Alge, &c., whilst amongst those 
which we obtained from the Channel Islands were many of a rich 
reddish brown tint, remarkably clean and fresh-iooking. As we 
received these specimens alive, we know the colour was not 
caused by any exposure of the shell to undue heat, but was 
perfectly natural. From further observations we are inclined to 
believe that specimens vary considerably in colour, according 
to the geological character of the district, which affects to some 
extent not only the nature of the sea-bed which forms their 
home, but also the marine fauna and flora by which they are 
surrounded. 
The ova of this species are very numerous and of a rich 
orange colour, attached in the usual way to the swimmerets of 
the female, and covered by the broad segments of the abdomen. 
They are exuded during April and May, and become a deep 
red, approaching to black as zoee matures. 
Pisa tetraodon is considered by Bell as ‘‘not common”; but 
although it may not be widely distributed it is certainly very 
abundant where it occurs, and we have obtained it from several 
localities in tolerable numbers; as, for instance, the Nore, the 
Channel (Sussex coast), and the Channel Islands. Dr. Leach 
mentions “‘the Isle of Wight, Teignmouth, and Brighton,” and 
Bell “the Dorsetshire coast and Bognor.’ M. Milne-EKdwards 
says it is very common on the shores of France and England. 
Mr. Lovett found large numbers of bleached and broken speci- 
mens on the beach at Shoreham in May, 1880, and quantities 
were thrown up in the same locality during the great storm of 
January, 1881. 
“eé 
Pisa Gibbsii, Leach. 
Although this species resembles the former in many of its 
general features, it differs from it widely in others. The form of 
the carapace is more flattened, also less rounded laterally; its 
margin is also less spinous, and its rostrum not so divergent at 
the extremity, though somewhat longer than that of P. tetraodon. 
Perhaps, however, its chief peculiarity, and at the same time 
one of the most remarkable features in the whole of the Decapoda, 
is the existence in Pisa Gibbsw of the dense covering of “ hair” 
