NOTES ON THE HABITS OF CERTAIN CRAWFISH. 81 
ware River, usually frequenting the rocky bed, but also, in fewer 
numbers, on the mud-bottomed portions of the river. They are 
usually found resting under flat stones, well out from the banks 
of the stream, where the water is of considerable depth. Wherever 
the vegetation is dense, we have failed to find them ; nor have we 
seen anything to indicate that it is a “ burrowing ” species. 
Dr. Hagen, in his “ Monograph of the North American Asta- 
cide,” which work we have followed exclusively in identifying the 
specimens we have collected, says, on page 62, “ The Astacus lim- 
osus Rafinesque (Amer. Monthl. Mag., t. 2, p. 42) from the muddy 
banks of the Delaware” is apparently the same species as Cam- 
barus affinis. While we have no reason, really, to doubt the cor- 
rectness of this assertion, we may say that the specimens we have 
collected during September were none of them from the “ muddy 
banks,” but from the bed of the river; although in such banks we 
found many crawfish, of a very different species, as we shall see. 
The Cambarus Bartonii, it appears to us, is the one burrowing 
species of this locality. We have found in the deep ditches, with 
precipitous, muddy banks, a medium sized crawfish, that in most 
respects, accords with the species called Cambarus Bartonii Fabr., 
by Dr. Hagen, on page 75 of his Monograph. 
We have purposely said “ in most respects,” inasmuch as there 
is a considerable range of variation between the many examples 
hat we have collected. Dr. Hagen says of this crawfish it ‘is 
the most variable species; as yet I cannot find stable and constant 
characters for dividing them into three or four species, as Mr. 
Girard has done.” 
It is this species, we doubt not, that Dr. Godman found near 
Philadelphia, and has referred to, as follows, in bis “ Rambles of 
a Naturalist,” which we find printed with the second volume of 
his “ American Natural History,” third edition: Philad., 1842. 
Dr. Godman says,— ‘I now returned to the little brook and, seat- 
ing myself on a stone, remained for some time unconsciously * 
gazing on the fluid which gushed along in unsullied brightness over _ 
its pebbly bed. Opposite to my seat was an irregular hole in the 
bed of the stream into which, in an idle mood, I pushed a small 
pebble with the end of my stick. What was my surprise, in a few 
seconds afterwards, to observe the water in this hole in motion, 
and the pebble I had pushed into it gently approaching the sur- 
face. Such was the fact; the hole was the dwelling of a stout 
AMER. NATURALIST, VOL. VII. 6 ; 
