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THE AMERICAN NATURALIST. [Vol. XXXVII. 



has been reported from widely separated localities. To what 

 extent this is dependent on the habits of the animals is difficult 

 to say, but the burrowing species obviously have a great advan- 

 tage over the others in their ability to occupy territory which 

 would be habitable to many of the species for but a very small 

 portion of the year. 



Only one species is found in salt water, C. uhleri, a species of 

 limited range, is found in salt marshes covered twice daily by the 

 tide, and also in brackish and fresh water where C. blandingii is 

 sometimes found associated with it. C. montezumce is said to 

 occur in salt water. 



Many observations have been made upon the blind species, 

 inhabiting caves and underground streams in Kentucky, Ten- 

 nessee, Indiana, Missouri and Florida, but they are not of a 

 nature to be easily summarized. The blind forms are not 

 confined to one group or section of the genus. The species are : 

 C. acherontis, C. setosus, C. hamulatus, C. pellucidus and C. 



Parasites, various species of Branchiobdella, have been noticed 

 on C. affims, C. bartonii, C. digue ti and Cambarus sp. and will 

 doubtless be found on many other forms, and C. digtieti is 

 recorded as being attacked by Temnocephala. 



Little has been recorded of the habits of the crayfishes during 

 the winter. It seems most probable that the stream inhabiting 

 species pass the winter in burrows in the bank or under stones, 

 etc., in the bed of the stream. The latter is sometimes the case 

 with C. virilis. The burrowing species seem quite generally to 

 spend the winter in the burrows, coming out early in the spring 

 and returning again when the water begins to become low as the 

 summer progresses. 



Observations have been made on the colors of the crayfish in 

 relation to its environment. One observer, working, for the 

 most part, on C. immunis, with fewer observations on C. pro- 

 pinquus, C. bartonii and C. diogems, concludes that the coloring 



According to him, the colors in all cases were similar to the 

 environment except in those with a red coloration. The red 

 color, he concludes, is due to the immediate effect of the sunlight. 



