568 PR0CEEDINO8 OF THE NATIONAL MDSEVM. vol.47. 



body of a female, lets go of the filament and fastens himself to the 

 female by his second maxillae and maxillipeds, and remains upon her 

 body for the rest of his life. Not being permanently fixed, he is 

 able to crawl about over the female's body, and is found sometimes in 

 one position, sometimes in another. But such motion is slow amd 

 laborious and probably is only practiced when necessary. Unlike the 

 female the male does not always lose his swimming legs, but may 

 retain them ; they become very small and dwarfed, however, and lose 

 all their swimming setae, so that they are no longer of any service as 

 locomotor organs. Furthermore the male does not increase in size 

 with successive molts like the female, but remains dwarfed, little if 

 any larger than in its copepodid stage. The mating of the sexes 

 in this family takes place upon reaching maturity, just after the molt 

 at the close of the second copepodid stage. But the male may remain 

 clinging to the body of the female long after this mating, sometimes 

 possibly throughout the life of the latter. 



Prehension. — The organs of prehension are the second maxillae 

 and maxillipeds. As explained elsewhere,^ the copepodid larvae, 

 both male and female, seize their host with the maxillipeds, rub 

 the frontal margin of the head against the skin of the gill arch or 

 fin until the outer end of the attachment filament is firmly glued 

 in place by means of the adhesive fluid it contains. As the coUed 

 filament is drawn out of the head, or subsequently, the larva grasps 

 its inner end between the claws at the tip of its second maxillae. 



Fasten,^ observing Salmincola edwardsii under the microscope, 

 describes its attachment as follows: . . . "As soon as the copepod 

 comes in contact with the filament of the gill its mouth parts (max- 

 illipeds) are inserted into the flesh, and by means of the powerful 

 claw-hke second maxillae it begins to rasp the filament until it forms a 

 cavity within it. As soon as this occurs, the anterior portion of the 

 copepod 's head, the frontal margin, is brought in contact with the 

 cavity and the inclosed attachment filament is injected into the hole. 

 The spherical mushroom body adheres to the flesh and the regenerat- 

 ing tissue of the gill soon incloses it tightly, thereby fastening the 

 organism firmly. The mouth parts are then withdrawn from the 

 flesh of the gill filament. In this condition the parasite remains 

 attached for a short time. Then the second maxillae detach the pos- 

 terior region of the attachment filament from the head margin and 

 they themselves become permanently attached to this end of the 

 filament." 



The exact time or even the method of attachment are specific or 

 generic in significance. That which concerns us in dealing with the 

 family is the fact that the larva is attached at the first by a frontal 



1 Proc. U. S. Nat. Mus., vol. 39, p. 2U. 2 Joum. Animal Behavior, vol. 3, No. 1, p. 56. 



