1852.] 89 
sutures of the carapace almost contiguous. Body uniform yellowish brown above 
and below, greenish on the sides and on the claws, the tips of which are red. 
This species, like C. fossor, burrows in the meadows. Such places we have 
visited in the neighborhoods of the city of Washington, in order to study its pe- 
culiar habits. The holes, as they appear at the surface of the ground, are nearly 
circular, from seven-tenths of an inch to one inch and one inch anda half in 
diameter. The depth of the burrows varies according to the locations; this, we 
generally found to be from sixteen inches to two feet, and sometimes to three 
feet and more. The construction of the burrow itself is often exceedingly 
simple: from the surface of the grouud the excavation exhibits a gradual slope, in 
direction more or less undulating for a distance from five to ten inches, when it 
becomes vertical forsix or eight inches, and then terminates in a sudden bottle- 
shaped enlargement in which the animal is found. The bottom of the burrow 
having no subterraneous communication, no other issue except towards the sur- 
face; it is entirely isolated from its neighbors, and leaves no chance for escape’ 
to its inhabitant. The same burrow may have several external holes connected 
with it, several inclined channels, which, however, meet at the depth where it 
becomes vertical. We found constantly the cavity full of water, but this was in 
March and April; the bottom, for several inches, was filled with a soft and pulpy 
mud. . 
There are other instances of burrows somewhat more complex. Their di- 
rection may be oblique throughout their whole extent, and composed of a series 
of chambers or ovoid enlargements succeeding each other at short intervals. Some- 
times also, and connected with one of the chambers, a narrow and nearly vertica! 
tubuliform channel extends downwards to a much greater depth, and appears to 
us as a retreat either during the cold winters or else during the dryness of the 
summer, when water is low. That it is not for the mere purpose of escaping 
pursuit, we infer from the fact that we repeatedly caught the animals in the 
chambers above, where they remained quietly instead of attempting to disappear 
_ into the apartments below. 
We generally found a single individual in one burrow, it being either a male 
or a female, the latter in March and April, carrying under the tail a bundle of her 
eges. Sometimes, when numerous individuals are gathered on a small space, it 
may happen that the windings of the upper part of their burrows will accidentally 
meet and have in this case a communication which was. not contemplated. Each 
individual, however, remains in its own apartment; so at least we constantly 
found to be the case. 
To accomplish the act of breeding, males and females must come together at 
one particular time. In one of the burrows which we examined we founda male 
anda female. We are inclined to believe that the male quits its retreat and 
goes in search of the female, as one individual of the former sex was found, 
at one time, walking over the surface of the ground. 
In the spring, and we are told in the fall also, the burrowing crawfish builds 
‘over the holes of its burrow a chimney of the maximum height of one foot, but 
most generally lower. This chimney, circularly pyramidal in shape, is con- 
structed of lumps of mud, varying in size, irregularly rolled up, and piled up, 
one upon each other, and intimately cemented together. Its exterior hasa rough 
and irregular appearance ; whilst the interior is smooth and as uniform as the 
subterraneous channel, having the same diameter as the latter. The cementing 
of the successive balls of mud is easily accounted for when we bear in mind that 
the latter are brought up in a very soft state, and that their drainage and subse- 
quent solidification on their exposure to the atmospheric air and rays of the sun, 
is all that is required to unite these parts. 
The animal works during night. How the work is performed has not yet been 
ascertained by actual observations. As to the question of the manner in which 
the mud is modelled into rolls or balls, either the tail, or perhaps the big claws 
might perform that part of the work. An observation made by John D. God- 
man* leads us to suppose that the mud is brought up embraced between the chest 
and the large claws. On an examination of these chimneys we detected the 
* Rambles of a Naturalist. Philadelphia, 1833, pp. 40, 41. 
