42 CONNECTICUT GEOL. AND NAT. I[IST. SURVEY. 



[Bull. 



Leptocheirus pinguis. Aug. lo to i8. 



Amphithoe rubricaia, Aug. 6 to 17. 



A. longimana, Aug. 13 to 17. 



Grubia compta, July and August. 



Jassa inarinorata, July 31 to Aug. 19. 



Ischyrocenis anguipcs. April and July 17. 



Cerapus tubularis, July 4, 21. 



Ericthonius rubricornis, Aug. 10. 



Unciola irrorata, May i ; July 13 ; Aug. 9, 18. 



Corophium cyUndricum, Jan. 5; July 17 to 21 ; Aug. 9 to 29. 



Caprellidas, March, July, August, and September. 



The number of eggs deposited at one time varies greatly in 

 different species. Observations have been made on a very few 

 species so that our knowledge is limited. Orchestia agilis carries 

 from seven to fifteen eggs, while one specimen of Callioplus 

 Icvz'iiisciihts, whose oostegites are unusually large (Fig. 17), 

 was found with nearly seventy eggs. 



Copulation seems to be in most cases an act quite independent 

 of the sexual condition of the individuals, although females 

 bearing eggs in the marsupium are practically never found with 

 a male. Holmes has studied the copulating of several species 

 arte finds that the recognition of the female by the male is purely 

 the result of chance which brings the two sexes into collision 

 with each other. That copulation takes place is due to the 

 difference in the reaction of the two sexes when in collision. 

 When two males collide both become active and for a few 

 moments strive to grasp each other but because of the mutual 

 activity fail to accomplish their end; when two females chance 

 to meet, both roll up and become quiescent and in a few moments 

 swim about as before. When, however, opposite sexes meet, both 

 pursue the tactics described above with the result that the male 

 grasps the female and swims off with her lying perfectly passive, 

 her body strongly flexed. In all the species observed the female 

 remains inactive save for the movement of the pleopods to main- 

 tain a respiratory current. 



In copulation the male ordinarily retains his hold of the 

 female by hooking the dactyls of his pereiopods beneath the 

 edges of the coxal plates of the female ; the gnathopods are used 



