18 



hard It molts within a few days after helng hronght Into cap- 

 tivity. On Aug. 17, a female with a soft shell and a male 

 crab which had been taken from the same hole about noon were 

 placed together In a compartment of a floating cage. At 

 5:45 P.M. they were observed to be copulating. On being dis- 

 turbed they separated. Their behavior was then observed 

 while copulation was resumed. The most significant point 

 with regard to this behavior was the apparent care with which 

 the male acted in order to inflict no injury upon the soft, 

 delicate shell of the female. 



During copulation the spermatophores are transferred from 

 the deferent duct to the portion of the seminal receptacle 

 that is lined with chitin, where they are deposited in a very 

 compact mass. Here they remain until the next spawning of 

 eggs. Only a portion of the sperms are used for the fertili- 

 zation of any one batch of eggs. One crab kept by itself in 

 a compartment of a floating cage for 69 days during the summer 

 of 1911, spawned six times sind apparently all of the eggs 

 in the six different batches of 500,000 to 1,000,000 eggs each, 

 were fertilized and developed normally. 



IV. Spawning Habits . 



The spawning habits and the development of this crab will 

 be discussed In a later paper. Here we shall present only 

 such points as are necessary in order to make it clear how the 

 stages in the entrance of the sperm and fertilization are ob- 

 tained. 



