SPAWNING HABITS OF CH.ETOPLEURA APICULATA. 245 



XV. 



August 20-22 : 



112 specimens collected August 20. 



ist night, no eggs and no spermatozoa. 



2d night, one female spawned lightly (300 eggs), also 



twenty eggs from another, and nine from a third. 

 3d night, one female spawned average number of eggs 

 (1,500), two others about 300 each. 



XVI. 

 August 24-26 : 



94 specimens collected August 24. 



ist night, no eggs, no spermatozoa. 



2d night, two males emitted clouds of spermatozoa ; one 

 female spawned good bunch of eggs, a second thirty- 

 two eggs. 



3d night, three females spawned lightly (100 to 300 eggs 

 each). 



Remark. Very light spawning since new moon. 



* Full moon, August 29. 



XVII. 

 August 28-31 : 



30 Chitons collected August 28. Left in supply department 

 in insufficient amount of water until 10 P.M. 

 (Fault of collectors.) 

 ist night, experiment set at 10 P.M.; no eggs and no 



spermatozoa. 

 2d night, two females spawned lightly and one male 



emitted spermatozoa. 

 3d night, two females spawned maximum quantity of 



eggs, 2,500 each. 

 4th night, no eggs. 



Note. The last experiment is more or less untrustworthy, be- 

 cause the chitons were partially suffocated by improper treatment 

 after collecting. The group, however, shows a distinct revival of 

 spawning in that thirty chitons spawned many times more eggs 

 than the larger group of the preceding experiments. 



