258 E. A. ANDREWS. 



and consisted of a very few specimens of Astacits {Cambaroides} 

 siinilis from Corea and some ten specimens of Astacus (Cam- 

 baroides] Japonicns from Hakodate, Japan. These last were 

 obtained by the " Albatross " from the market in July, 1906, and 

 were remarkable in being all strung along upon bits of stick that 

 had been thrust through several crayfish, one after the other, 

 passing through the head-thorax and abdomen lengthwise. From 

 the condition of internal anatomy the specimens would appear to 

 have been dried before they were preserved by the naturalist. 



Observations upon Cainbanis have shown that when the sty- 

 lets are being used to fill the sperm receptacle the male is firmly 

 fastened to the female by two pairs of hooks, or spines, that 

 stand out like spurs from the walking legs and are carefully 

 fitted into the groove between the segments of the legs of the 

 female. In fact, experiments show that without these spines the 



FIG. i. 



other organs are of no avail as the male is not able to transfer 

 the sperm to the sperm pouch. In Cambarns there are then 

 three sets of necessary external organs concerned in sperm 

 transfer, the hooks and the stylets of the males and the sperm 

 receptacles of the females. 



In Canibaroides the hooks are present as well as the stylets 

 but in the females there is no discovered receptacle though the 

 annular plate is somewhat modified. 



We will describe these three sets of organs, in the following 

 order : hooks, stylets, annular plate of female. 



