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. fo.tsorj 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 and a 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 for six or eight inches, and then terminates jn 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 hlled 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 vertical 

 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 

 eggs. 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 found a male 

 and a 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 loot, 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 has a 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. 



