314 



Geofifrey Smith 



The normal uninfected specimens of the male oecur during the 

 hreeding season (February to August under three chief forms which 



Iterm low, middle 

 and high. These 

 are drawn Sehe- 

 rn atically in the 

 Text Figures 1, 

 2 and 3 respec- 

 tively. The se- 

 condary sexual 

 charaeter aflfected 

 is the chela, 

 which in the low males is slightly 

 swollen, and in the high males is 

 relatively to the size of the crab 

 much more swollen, while bet- 

 ween these two types comes tbe 

 middle male in which the chela is 

 hardly more developed than it 

 is in the feraale. The low males 

 measure in carapace length between 

 13 and 15 mm., the middle males 

 16—18 mm., and the high males 

 19— 2G mm. Duriug the breeding 

 season the number of middle males is small, compared to the 

 frequency of the other two types. We may express the relation 



Fig. 3. 



