122 NATHAN FASTEN. 



pear-shaped spermatophores (Fig. 2, 5). The spermatozoa are 

 manufactured in the testes, from which they are conducted into 

 the vas deferens, and from here they are then conveyed into 

 the spermatophores, where they are stored until the male .is 

 ready to fertilize the female. Located near the spermatophores, 

 on the ventral side of the body are two openings, the ejaculatory 

 pores (Fig. 2, e), through which the spermatophores may be 

 extruded. 



Fertilization in the Lernaeopodidse occurs shortly after the 

 attachment of the free-living copepods to the host. In Sal- 

 mincola edwardsii it takes place about two and one half to three 

 weeks after attachment, and in the species under consideration, 

 Salmincola beani, although the time of fertilization has not been 

 accurately determined, it, in all probability, takes place after a 

 similar lapse of time. When the copepods are ready for fertili- 

 zation, the male is about one third or one fourth the size of 

 the female. 



Prior to fertilization the males and females hang side by side 

 on the gills of the host, being attached by the so-called attachment 

 filaments. In the male, the attachment filament remains long 

 and tubular, with an enlarged bulla-like structure at one end 

 which is firmly fastened in the flesh of the gill, while the opposite 

 end is slightly enlarged and to it are attached the terminal claws 

 of the male's second maxillae. In the case of the female, the 

 tubular portion of the attachment filament disintegrates shortly 

 after the attachment of the female to the host, so that only the 

 bulla-like portion remains for the attachment of the parasite. 



In order to effect fertilization the male must seek out a female, 

 release his hold on the gill, and then in some way become attached 

 to the posterior margin of the female's body, in the region of 

 the genital pores. The specific manner in which this is accom- 

 plished is as follows : When the male reaches maturity he under- 

 goes circling movements. If he meets a female in the radius 

 of his explorations, he grasps her body with the terminal claws 

 of his free maxillipeds and at the same time releases his hold on 

 the attachment filament. The male now creeps over the body 

 of the female until he reaches the neighborhood of her genital 



