268 KANSAS UNIVERSITY QUARTERLY. 



nes is the only crayfish yet reported from Colorado. In a letter of 

 October 12, 1900, he says: "We find crayfish here in ditches 

 and ponds much as in other localities, but as most of the ditches 

 are dry part of the year the animals are not abundant. Our streams 

 are mostly swift running and crayfish are seldom found in them. 

 I have not noticed the animal at high altitudes but they may occur 

 there, doubtless up to 8000 feet at any rate." 



5. Oambarus immunis Hagen. 



C. immnnis, Hagen, '70, male, F. I, and female, with figs, of 

 chela, epistoma, lamina, "spina externa," and abd. app. of male, 

 F. I. 



C. signifer, Herrick, '81, with fig. of rostrum, lamina, and abd. 

 app. of male, F. I and II. 



C immunis, Forbes, '76, male, F. I and young. 



Notes on variation and literature, Faxon, '85. 



C. immunis, Hay, '96, with sketch of carapace, lamina, annulus 

 ventralis, and abd. app. of male, F. I and II. Also Notes on 

 Habits. 



Habits, Harris, '01. 



1. Leavenworth, (coll. Acad. Nat. Sci., Phila.) (Faxon, '85). 



2. Ellis, coll. G. H. Gilbert (Faxon, '85). 



3. Douglas county, in stagnant ponds (coll. U. of K.). 



C. immunis is to be looked for in shallow, stagnant ponds and 

 roadside ditches where it is often found in immense numbers. 

 Upon the drying up of the ponds the animals retire to burrows 

 along the edge. For a more complete discussion of the habits of 

 this species see Harris, '01. 



5a. Oambarus imraunis Hagen, var. spinirostris Faxon. 



C. immunis, var. spinirostris Faxon, '85, male, F, II and female, 

 with fig. of cephalothorax of male, F. I. 



C. immunis var. spinirostris, Faxon, '85 b, male F. I. 



C. immunis var. spi?iirostris. Hay, '98, with sketch of carapace. 



1. Ward's Creek, Shawnee county (coll. Washb. Coll.), F. W. 

 Cragin and J. B. Fields, coll. (Faxon, '85 b). 



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



6. Oambarus nais Faxon. 



C. nais, Faxon, '85, b. 

 C. nais, Faxon, '90. 



I. Labette county (coll. Washb. Coll.), W. S, Newlon, coll. 

 (Faxon, '85 b). 



