168 KANSAS UNIVERSITY SCIENCE BULLETIN. 



stances was he able to get reports of females " in berry" later 

 than June, and then but a single individual in each case. Hay 

 reports C. diogenes as in copulation in the open water April 2, 

 eggs being laid from April 18 to 30. Harris ('02) reports a 

 female with eggs in a not very late stage of development May 3. 

 The taking of a female with eggs nearly ready to hatch on New 

 Year's day, as recorded by Bundy ('77), forms an interesting 

 exception to the above observations and suggests the laying of 

 eggs in the fall, as has been observed in other species. The 

 occurrence of a single individual or of a male and female in a 

 burrow, as has been recorded by different observers, requires 

 careful observation before any significance at all can be attribted 

 to it in this connection. The suggestion which has been made 

 that the burrow is designed as a retreat for the female while 

 the eggs are hatching is no longer tenable, but that much of 

 the period of development may be passed in the burrow is also 

 beyond doubt. 



Harris ('00 and '02) finds C. gracilis with a few young, about 

 old enough to leave the parent, in the open ponds in early spring, 

 and suggests that those with no young must have lost them 

 before or immediately upon leaving the burrows in the spring. 

 The most of the process of hatching must take place in the bur- 

 rows. Hargitt ('90) noticed crayfish (C. gracilis f) copulating 

 in aquaria in the spring. 



In C. simulans, another of the burrowing species, Harris ('02) 

 reports females taken from burrows late in August with eggs 

 apparently recently laid. Mrs. Cockerell states that C. gallinas 

 (or C. simulans) taken in May had the swimmerets loaded with 

 eggs. The differences in time are certainly interesting. 



C. immunis is found in the open ponds with eggs, in the fall, 

 and the females appear in the ponds, where the hatching of the 

 eggs is completed, early in the spring — about March 21. 



Hay ( '96) reports C. arglllicola with young as early as April 2. 



Harris ( '02 ) records C. neglectus with eggs and young in early 

 June in the cold water at the mouth of a large cave in the 

 Ozarks, and attributes the absence of eggs or young on other 

 specimens taken in the region to the low temperature of the 

 water at the mouth of the cave, which would retard the hatch- 

 ing of the eggs. Under C. virilis (15, ? 27 ) is noted a speci- 

 men, which may be C. neglectus, with eggs April 13. 



