BRITISH STALK-EYED CRUSTACEA. iy) 
Association Report for 1866, but beyond that records seem 
scarce. 
The carapace of this species is somewhat cylindrical, with an 
acute triangular rostrum, and a raised medial line down the 
whole length of the carapace; the anterior feet possess long, 
compressed, grooved, and granulated fingers; the second pair 
are similar, but much smaller, and the remainder are simple. 
The abdomen is shorter and less cylindrical than other 
burrowing forms, and the colour of the animal is a pale pink 
or rose. 
One of the most wonderful characteristics of this species 
alluded to by Bell is that it possesses eyes of a rudimentary 
character, having neither colouring pigment nor corner ; and he 
states that, as this crustacean occasionally inhabits depths of 
one hundred and eighty fathoms, where it burrows in the soft 
mud, distinct vision would be useless. This is an exceedingly 
interesting fact, and doubtless the great depth of its habitat, 
and the fact of its being also a burrower, accounts for its being 
usually termed ‘ rare.” 
Astacus fluviatilis, Auct. 
This sole representative of our fresh-water Stalk-eyed Crus- 
tacea is widely distributed, and should be by this time well 
known, not only on account of the early writings of Réaumur 
and Rathke, but especially by reason of that valuable work by 
Prof. Huxley entitled ‘ The Crayfish: an Introduction to the Study 
of Zoology.’ The mere mention of this work will show how 
unnecessary it would be for me to enter into any description 
of this animal in a paper like this, so that I shall merely give 
an outline of its characteristic features, together with a few 
observations of my own upon its habits. 
Astacus fluviatilis is very much like a small lobster, which, 
instead of being smooth and black, is somewhat rough and of a 
dirty greenish brown colour: this tint, however, varies con- 
siderably, owing, I am inclined to think, to the nature of the 
locality in which the particular specimens are obtained. I have 
Seen some of a rich warm sepia-brown, others of a pale sage- 
green, and others again of a bluish tinge; but the usual pre- 
vailing colour is, as I have said, of a dirty-looking greenish 
brown, so much resembling the bottom of a stream that it is 
ZOOLOGIST.—JAN. 1885, c 
