270 KANSAS UNIVERSITY QUARTERLY. 



10. Osage river, LaCygne, Lynn county (Faxon, '90). 



11. Topeka, Shawnee county (Faxon, 'go). 



12. Spring at head of Medicine Lodge river, Kiowa county 

 (coll. Washb. Coll.). 



13. Stagnant ponds, Douglas county (coll. U. of K.), 



14. Rock creek, Douglas county (coll. U. of K.), C. D. Bunker, 

 coll. 



15. Washington creek, Douglas county (coll. U. of K.). 



16. Coon creek, Douglas county. 



17. Wild Horse creek, Jefferson county (coll. U. of K.). 



18. Dickinson county (coll. U. of K.), Walter Meek, coll. 



ig. A small branch of Chikaskia river, six miles northwest of 

 Caldwell, Sumner county (coll. U. of K.), T. J. Kinnear, coll. 



20. Small stream near Egerton, Wyandotte county (coll. U. of 

 K. ), Miss Metta Haines, coll. 



21. Labette creek, within city limits of Parsons, Labette county 

 (coll. U. of K.), R. B. Brewster, coll. 



22. It might not be out of place to add that I have seen material 

 collected in Kansas City, Missouri. 



C. virilis is found principally in running streams, although it is 

 frequently taken in the same locations as C. immunis. While I 

 have never taken C. virilis from burrows, I have no doubt that the 

 great numbers of burrows which we see running back into the banks 

 of the creeks just a little below the water-line belong to C. virilis. 

 When living in the same sort of location as C. immunis it doubtless 

 burrows in the same manner. A specimen from Kansas City, Mo., 

 handed me for study by Mr. R. E. Scammon,, was found by labor- 

 ers nine feet under ground and over one hundred feet from water. 



C. virilis seems to prefer rocky rather than muddy places. May 

 5, 1900, I collected this species in Wild Horse creek, Jefferson 

 county. At the rocky 'riffles' the crayfish were taken in abund- 

 ance, but, perhaps, 150 yards above, where the bottom was com- 

 posed of soft, deep mud I did not secure a single specimen. I 

 have noticed the same thing in Coon creek, Douglas county, and 

 my friend, Mr. C. D. Bunker, tells me that in Rock creek, Douglas 

 county, he has noticed that the animals are to be found only in the 

 rocky places. 



I cannot say whether it is a dislike on the part of the animal for 

 the mud which causes it to select the rocky parts of the stream, or 

 whether it finds among the rocks more ready protection from its 

 enemies. So far as 1 have been able to observe, food would be 

 just as plentiful, if not more so, in the slower-running, muddy 



