108 CHARLES BRANCH WILSON 



lateral margin. In the present genus, on the contrary, the basal 

 joint of the first legs is turned backward parallel with the body 

 axis, and the rami also point in the same direction. Moreover 

 if either of them were broken off its absence would be very 

 apparent. It is worthy of note also that the second legs in 

 Dana's genus stand at right angles to the body axis, and that 

 the two rami are attached to the lateral margin. In answer to 

 Stebbings's criticism wiht reference to the relative size of the 

 genital segment compared wiht the carapace, it is sufficient to 

 say that this does not constitute a generic character among the 

 parasitic copepods. 



The present specimens accordingly give us a new locality 

 and two new hosts for this species. This male differs from the 

 one described for pinguis in the following particulars. Here the 

 carapace is longer than the rest of the body; in pinguis it is 

 considerably shorter. Here the free thorax and genital segments 

 are all the same width, while the abdomen is abruptly narrowed 

 to half that width; in pinguis the first free segment is three- 

 fifths as wide as the carapace and the following segments are 

 narrowed regularly, the abdomen being but little narrower than 

 the genital segment. Here the posterior corners of the genital 

 segment are armed with the fifth legs, which are very prominent 

 in dorsal view; in pinguis the fifth legs are entirely lacking. 

 Here the terminal claw on the maxillipeds shuts down between 

 large knobs on the basal joint, making it chelate; in pinguis 

 there are two claws shutting past each other like scissor blades. 



Philorthragoriscus serratus (Krøyer). 

 Eight young females in the chalimus stage were taken from 

 the fins of Squalus acanthias at Newfoundland. A second lot 

 of three females and one male, and a third lot of six young 

 males were obtained from the same host and locality. Hitherto 

 this species has been found on the outside surface of the sunfish 



