for her defenseless body not by hiding in the bot- 

 tom, but under the shielding bosom of her hard- 

 shelled mate. Often prior to such molting, she is 

 carried about by him, after which — while she is 

 still in the soft-shelled stage — fertilization is ef- 

 fected. The copulative embrace lasts for a couple 

 of days. Indeed, so tenacious was the male's hold 

 on the female when these were taken that even the 

 experience of the trawl and the subsequent trans- 

 ference to my tanks failed to disturb their atten- 

 tion. On this occasion — the only instance in the 

 lifetime of the female wherein devolves upon her 

 this biological function of her sex — her sperm sacs 

 become sufficiently filled to fertilize all the eggs 

 she will lay during the remainder of her days. The 

 eggs are not fertilized while they are still retained 

 in the ovaries ; they meet with the male element as 

 they pass through the sperm sacs when leaving the 

 ovaries for the exterior, at the time of spawning. 

 If mating occurs very early in summer, it is pos- 

 sible for her to have a clutch before autumn; how- 

 ever, the season of mating is usually in late July or 

 early August and the eggs are then not laid until 

 late in the following spring or in the summer. Dur- 

 ing the course of her life, subsequent to this single 



[253] 



