150 Vniversitij of Calif oniia Publications in. Zoology [Vol. 16 



is observed at about the last of June. Even before this time some 

 have shed their young. They continue to hatch in large numbers 

 through July and well on into August. Here and there one may find 

 cases in which they have not hatched until the middle of August. 

 Roughly the breeding season may be said to extend through May, 

 June and July. A set of eggs probably requires from nine to ten 

 weeks for hatching. These statements are based upon personal 

 observation only as regards the termination of the spawning season. 

 It has been necessary to accept the statements of the more intelligent 

 and reliable fishermen as to the time of its commencement. 



The eggs are attached to the hairs upon the pleopods of the female. 

 At first they are of a scarlet color but change later to maroon and 

 dark brown as the larvae develop. 



There is no difficulty in securing the young. It is only necessary 

 to impound spawn-bearing females. The young hatch very readily 

 even after the spawn-bearing parent has been kept in captivity for 

 weeks. Attempts to rear them, however, proved futile. Their extreme 

 delicacy and pelagic habit make their culture an especially difficult 

 problem. 



A few observations were made to determine the amount of spawn 

 carried by the females of different size. They resulted as follows : 



These weight determinations were made after drying the super- 

 fluous moisture from the eggs by spreading them out upon filter paper. 

 The results give a fair basis of comparison because the spawn was in 

 each case treated uniformly. A careful estimate of the number of 

 eggs carried by the fourteen-inch female showed it to be approxi- 

 mately 500,000. This was based upon a careful count of a weighed 

 portion of the mass. 



Examination of the catches of spiny lobsters made during the 

 breeding season leave no doubt that, in general, they spawn each 

 year. It is always possible to find some adult females that do not 

 bear spawn, even at the height of the breeding season, but the pro- 

 portion is always small at that time and may be chiefly explained by 



