no. 140-f. PARASITIC COPEPODS—CAIIGIDJE— WILSON. 547 



seemed to push itself backward with its maxillipeds. In this way the 

 secretion was pulled out into a long- slender rod or cord, nearly as long 

 as the body of the larva. 



The secretion seems to harden instantly and furnishes a strong and 

 very flexible means of attachment during the moults which intervene 

 before the adult stage is reached. 



If one of the fin rays be examined under the microscope the filament 

 can be seen to penetrate the skin and to be attached along the side of 

 the ray for some little distance, as noted by Scott (1901). Often the 

 tip of the filament is spread out into a broad disc, giving it a firmer 

 hold around the ray. 



Just how the secretion is brought in contact with the fin ray could 

 not be determined, but it has already been noted that the second 

 antennae, in grasping the fin, penetrated the skin and took hold on the 

 ray. It seems probable that in spreading the secretion about some of 

 it may enter the openings thus made and come in contact with the ray. 

 Its own adhesiveness would be sufficient to fasten it securely on 

 hardening. 



In all the specimens collected the tip of the filament has been so 

 firmly fastened to the host that it could not be detached. In every 

 instance the filament either broke at the center or was torn out of the 

 chalimus's carapace when an effort was made to detach it. And the 

 only way to obtain the fastening intact is to cut off the ray and pre- 

 serve it with the chalimus still attached. 



The larva is frequently attached to a scale rather than a fin, and in 

 such cases the filament pierces the cutis covering the scale and is flat- 

 tened into a disk upon the surface of the scale itself. The idea in 

 every instance seems to be the attachment of the distal end of the fila- 

 ment to something that will not give way. In rare instances the 

 young may be found attached elsewhere upon the host, or even to 

 some portion of the body of an adult parasite, as noted by Hesse (1858). 



The chalimus can pull itself down to its host at any time by means 

 of its long maxillipeds, and in this way obtain its food. The stage is 

 one of great interest, both on account of this peculiar means of attach- 

 ment and also historically. 



Originally discovered by Burmeister, it was described by him in 

 L831 as :i new genus of the Caligidse, and several species were after- 

 wards added by the same and other authors. But the more careful 

 observers were quick to suspect its real relation to other members 

 of the family, and Kroyer very early suggested that it was onby 

 the young of <'<i//<jhs. or some closely related form. Midler (1S5'2) 

 and Stein (1852) soon proved this satisfactorily, and subsequently 

 Hesse I L858), Gerstaecker (1859), and Nordmann (1864) confirmed the 



conclusion. 



Of these writers 1 1 esse had the notion that the mother voluntarily 



