90 [May, 



imprints of the second and third pair of claws, which indicate, evidently, that 

 the parcels of mud, once brought to the surface in the iTianner just stated, are ar- 

 ranijed and fixed in their definitive place by means of these organs. 



When the work has thus been carried on towards completion, the last touch- 

 consists in shutting up the aperture. This is accomplished by means of several 

 balls of mud. brought up from underneath, deposited temporarily on the edge of 

 the chimney and drawn back in close contiguity, so as to intercept all commu- 

 nication with the external world. 



The number of such chimneys is sometimes very great in one particular lo- 

 cality, distributed without any geometrical regularity, and recalling to mind the 

 scattered habitations or village of a newly settled colon}^. 



Whether C diogenes is to be found in other places besides the meadows, 

 we are not prepared to state definitively. We have seen localities where the 

 holes could be traced from the edge of the rivulets to the middle of the 

 meadows, still, there being no subterraneous communication from one burrow to 

 the other, the animal, at any rate, would have to crawl out of the water and 

 walk over land. Colonies of burrowing crawfish are found, we are told, in the 

 interior of lands, far away from any rivulets or waters, a circumstance which 

 would lead to the supposition that these at least pass their entire life in such 

 localities instead of spending one season in the waters and another in dry lands. 

 For, one fact must be very apparent, the existence of several species of craw- 

 fishes with burrowing habits, even in the hypothesis of an identity between 

 C. fossor and C. diogenes. For we learn from Mr. T. R. Peale, of Washington, 

 that chimneys of mud, in all points similar to those just described, were ob- 

 served by him in New Grenada, along the Rio Magdalena, several hundred miles 

 from the sea shore, and consequently indicating the presence there of a species 

 of crawfish which we do not hesitate in pronouncing distinct from C. diogenes. 



It remains now to ascertain how many such there are, and whether some of 

 them are not to be found both in the running waters of the rivulets and in the 

 meadows. 



12. CAMBARTrs LONGULUS, Girard. Rostrum of the same proportional length 

 as in C. diogenes, but it is narrower and slightly concave on the sides. The 

 dorsal area between the sutures of the carapace is very broad, a character which 

 at once distinguishes it from the preceding species. From C. Bartonii it differs 

 by a much more elongated and narrower rostrum. 



Locality. Uncertain; labels having been accidentally lost. Its range, however, 

 is within the middle States of the Union. 



13. CambarT'S pusiLLTjs, Girard. Astacus picsilluSi'RKViti. Amer. Monthly 

 Mag. II, 1817, 42. 



This species comes nearest to C.mo7ita7i?is, hut the antennae are still longer and 

 the rostrum more tapering, and terminated by a more elongated point. The 

 dorsal area between the sutures of the carapace is likewise narrower. 



Localities. Lake Ontario, three miles from shore opposite Oswego, taken in 

 the stomach of Lota maculosa (Baird). Brooks near Saratoga, Lake George, 

 Lake Champlain, Utica, Oswego, (Rafinesque). 



14. Cambartjs robttstus, Girard. Differs from C. Bartonii by stouter an- 

 tennae, composed of shorter articulations and by proportionally more elongated 

 and more conical rostrum and a more acute terminal point- From C.pnsilhis it 

 is distinguished by having shorter antennae, besides a difference in the shape of 

 the rostrum. The dorsal lines of suture of the carapace, on the other hand, do 

 not approximate as much as in C. diogenes., although nearer than in both C Bar- 

 tonii and C. pusillns. It differs from C. longalas by a broader rostrum and a 

 narrower dorsal area. The anterior pair of abdominal legs in the male, more- 

 over, is flattened and twisted. 



Locality. Humber River, near Toronto (Canada). 



15. Cambarus Gambelii, Girard.^-Antennae, about the length of the body, 

 from the tip of the rostrum to the origin of the tail. Rostrum proportionally 

 long and conical as in C. diogenes and C. longnlt/s, but is bordered on each side 

 with a row of minute and conical tubercles. Anterior claw very stout, bearing 



