No. 503] CAMBARUS BABTONIUS BARTONI 713 



At 10:30 P. M., five more tadpoles were gone. At 9 

 A. M., on Friday, only 5 were left, one of these being 

 dead. This was a record of 22 out of 27 active tadpoles 

 in 16 hours. The female was seen to catch several of the 

 tadpoles, using- for this, not her cumbersome chelae, but 

 her smaller, nimble, first pair of ambulatory appendages. 



Evidently Cam bants barton ins bartoni is capable of 

 catching toad tadpoles, but it is improbable that many 

 are caught, for I am informed by Mr. Newton Miller that 

 the young tadpoles, although near the shore during the 

 day, go to the deeper water at night. It is at night that 

 the crawfish come into the shallower water near the shore, 

 and even part way out of the water. Here it is that they 

 may catch an occasional fish, frog or toad. 



Two young frogs were kept during the greater part 

 of the winter in one of the aquaria on my desk with the 

 crawfish, but none of the dozen seemed able to kill them. 

 Once I forced a frog to swim down to one corner of the 

 tank where several crawfish were collected, and one of the 

 crawfish grasped a hind leg with his right chela, and a 

 moment later secured the front leg on the same side with 

 his left chela. He then forced the frog to the bottom 

 and attempted to pull him limb from limb, all the time 

 holding the animal under water. In just a moment, how- 

 ever, the frog kicked with his free hind leg, and accident- 

 ally striking the crawfish on the carapace, was released. 



My observations and experiments in the laboratory were 

 supplemented by many evenings spent on the shores of 

 several small ponds near the university, observations be- 

 ing made by means of a strong acetylene light. I believe, 

 in the light of these observations, that the crawfish in the 

 still water aquarium behaved normally. 



In the spring, the crawfish is very active, and feeds 

 with much more eagerness than during the winter. It 

 is then, too, that the interesting phase of the mother's care 

 of the eggs may be best seen. 



On account of this, I took occasion to watch a pair of 

 crawfish, a male, and a female with eggs just about ready 



