HARRIS: CRAYFISHES GENUS CAMBARUS. 3 35 



are seen running back into the banks of the creeks just a little 

 below the water line belong to this species. When living in the 

 same sort of habitat as C. immunis, it doubtless burrows in 

 the same manner. A specimen from Kansas City, Mo. (24, 8) , 

 was found by laborers nine feet under ground and consid- 

 erably over 100 feet from water. C. virilis seems to prefer 

 rocky rather than muddy places. May 5, 1900, he collected 

 this species in Wild Horse creek, Jefferson county, Kansas. 

 At the rocky riffles the crayfish were taken in abundance, 

 but perhaps 150 yards above, where the bottom was composed 

 of soft, deep mud, he did not secure a single specimen. The 

 same thing was noticed in Coon creek, Douglas county, Kansas, 

 and Mr. C. D. Bunker told him that in Rock creek, Douglas 

 county, Kansas, he noticed that the animals are to be found 

 only in the rocky places. Perhaps it finds among the rocks 

 more ready protection from its enemies. So far as could be 

 seen, food would be just as plentiful, if not more so, in the 

 slower running, muddy parts of the stream than at the rocky 

 rifiles. C. virilis can and does live in muddy places. It is 

 sometimes found in muddy ponds and roadside ditches with 

 C. immunis, and he took a great many from Washington creek, 

 Douglas county, Kansas, when the mud was as soft and deep 

 as in either of the creeks mentioned above. In the winter C. 

 virilis may be found under flat stones in the rocky creeks, even 

 when the water is covered with ice. When taken from the 

 water, they are so numb as to be almost incapable of movement, 

 but liven up when held in the hand for a short time, and are 

 as lively as ever after a few hours in the laboratory. 



The eggs are laid in the spring, none being found on the fe- 

 males collected during the winter. The ovarian eggs of speci- 

 mens taken in January seem to be fully developed, so far as 

 may be seen from examination with the naked eye. Harris 

 ('02) gives two lots of material as taken under stones in shal- 

 low running water. 



Cambarus weigmanni Erichs. 



Mexico. 



1. Mexico. (F., '85.) 



?2. [Gulf of Mexico], Jalapa [Jalapa]. (F., '85.) 

 ?3. [Gulf of Mexico], Isthmus of Tehuantepec. (F., '85.) 



