72 FAUNA OF MAYFIELD'S CAVE. 



an animal, which at best could probably catch very few of them. While 

 some decaying organic matter is being continually brought into the 

 cave through sink-holes, it is carried in in quantity only at time of high 

 water. 



Putnam (1875, 16) records the following observations as to the taking 

 of food by Cambarus pellucidus. 



The iblind species * * * darts back as soon as the food is dropped into the 

 water and then extends its antennas and stands as if on the alert for danger. After 

 a long while, sometimes from fifteen to thirty minutes, it will cautiously crawl about 

 the jar with its antennae extended as if using them for the purpose of detecting 

 danger ahead. On approaching the piece of meat, and before touching it, the animal 

 gives a powerful backward jump and remains quiet for a while. It then cautiously 

 approaches again, and sometimes will go through this performance three or four 

 times before it concludes to touch the article, and when it does touch it the result is 

 another backward jump. After another quiet time it again approaches, perhaps only 

 to jump back once more, but when it finally concludes that it is safe to continue in the 

 vicinity of the meat, it feels with its antennas for a while and then takes the morsel 

 in its claws and conveys it to its mouth. 



I have made practically the same observations and have noted that 

 individuals kept in capitivity for some time may become less wary in 

 taking food. 



Very young individuals were seen during February and March, the 

 earliest date being February 17. I saw quite young ones at no other 

 time of the year. I did not observe copulation nor see the females 

 with eggs. 



Packard (1888, 110-112) found that the eye of C. pellucidus had lost 

 ' 'the facets and entire cornea, the cones and rods, and the three black 

 pigment layers/' that the "integument of the eye, with its stalk, is 

 present but abnormally lessened in size," and that "the optic nerves 

 and ganglia are present, but the latter are small and degenerate." 

 Parker (1890) , on the other hand, describes the eye as degenerate, but 

 as not having degenerated far enough to lose the cone cells. Besides 

 its degenerate eye this species possesses other well-known characters 

 adapting it to cave life. It is without black pigment, its body is slender, 

 its legs are long and slender, and it has quite long and delicate antennae. 

 Further, in common with other cave crayfish, its antennal scale has 

 become very broad. 



Another blind crayfish, Cambarus setosus Faxon (1889, 625), comes 

 from the caves of southwestern Missouri. This species has degenerate 

 eyes more degenerate than those of C. pellucidus according to Parker 

 (1890), less according to Faxon (1889, 628) is white in color, has slender 

 body and appendages, and a wide antennal scale. Cambarus hamidatus 



