228 C. L. TURNER. 



examined and all have displayed only normal secondary sexual 



characters. 



Specimens from Turtle Creek. 



Since Turtle Creek forms the only outlet of Delavan Lake 

 special attention was given to this creek and collections were 

 made from the creek at three localities about eight miles apart. 

 Of 263 females of Cambarus virilis collected a single one had the 

 copulatory hook on the left third walking leg and was otherwise 



normal. 



Specimens from Ponds. 



A collection which was made in the spring and summer of 1922 

 from the ponds about Beloit was examined and out of 309 

 specimens (137 females) one female was found which had a 

 copulatory hook on the left third walking leg. 



Specimens from Rock River tributaries exclusive of Turtle Creek. 



Collections were made from four small tributaries of Rock 

 River, all within a radius of twenty miles and all females taken 

 were normal. A collection of eighty females taken from Sugar 

 River, a larger tributary of the Rock River, contained two 

 aberrant female specimens each of which bore a copulatory hook 

 on one of the third walking legs. 



Specimens from Northern Wisconsin. 



A small collection purchased from a supply by the I'niversity 

 of Wisconsin contained sixty females two of which had copulatory 

 hooks on both third walking legs. Through correspondence with 

 the supply company it was learned that the specimens came from 

 somewhere in northeastern Wisconsin. 



SUMMARY OF FEMALES WITH MALE CHARACTERISTICS. 



1. In Lake Delavan 88 per cent, of the females of Cambarus 

 virilis displayed at least one set of male characters, namely, male 

 cdpulatory hooks on the third walking legs. 



2. An old female from Lake Delavan carried in addition to the 

 copulatory hooks a pair of small but distinctly male-like ap- 

 pendages upon the first abdominal segment. 



3. Outside of Lake Delavan six females have been collected 

 which had copulatory hooks on one or both third walking legs. 



