HARRIS : CRAYFISHES GENUS CAMBARUS. 99 



found it burrowing in the low grounds on the prairies [at Racine, 

 Wis.] , emerging from its holes at nightfall and after rains. 



Faxon ('85) states that according to Dr. P. R. Hay, C. gracilis 

 burrows in the clay in the prairies near Racine, Wis., and that 

 Professor Forbes reports it as common along the watercourses in 

 early spring in the neighborhood of Normal, 111. 



Being a burro wer, C. gracilis is one of the species that is 

 hard to obtain, especially the males, and this probably accounts 

 for the meager reports of its distribution. 



Mr. H. Garman says (Faxon, '85) that he has examined 

 hundreds of specimens taken along watercourses in the neigh- 

 borhood of Normal, 111., and has not found a dozen males. 



Hay ('95) says: "It is a burrower, coming forth probably 

 only during the breeding season in the early spring, when it in- 

 habits the watercourses." 



Harris ('01) notes its presence in shallow, stagnant ponds in 

 the neighborhood of Lawrence, Kan., in company with C. 

 virilis and C. immunis. These ponds are usually very muddy, 

 and have usually, in the shallow parts, which are apt to become 

 dry during the summer, a rank growth of Polygonum and plants 

 of like habit. 



Harris ('00) records material as very plentiful in these stag- 

 nant ponds in early spring, but never knew of material being 

 taken in running creeks. In one pond, which was carefully 

 watched, the females appeared March 13, while the males were 

 not found until April 15, when one was secured, another being 

 taken some days later at the top of its burrow in a pasture not 

 far from the pond. In August two males and one female were 

 taken from the mouths of their burrows in a yard some distance 

 from a running stream, but where the ground was low and in- 

 clined to be somewhat moist. The animal does not seem to be 

 entirely nocturnal in its habits, and is not infrequently found 

 at the top of its burrow in the daytime. The lowlands in 

 which this species lives are frequently flooded at times of great 

 rainfall, in which case the animals leave their burrows, and 

 upon the subsidence of the water may be found wandering over 

 the surface of the ground. The females of the species are 

 olive-green. in color, the males almost a salmon-red. The writer 

 had been told by people from various parts of the state ( Kansas) 



