no. 1404. PARASITIC COPEPODS—CALIGIDM-WILSON 579 



ages are doubly edged with a finely pectinated membrane. Second 

 maxillipeds large and stout, the basal joint much swollen and at least 

 a third longer than the terminal claw. Furca short and very stout, 

 the base longer than the branches, which are straight and slightly 

 divergent, the same diameter throughout and very blunt at the tips. 



Of the swimming legs the three terminal spines at the tip of the first 

 pair are short, obtuse, and about the same length. 



The seta at the outer corner is also short and naked; the plumose 

 setae on the posterior margin are large, with very short pinnules on the 

 outer margins, but of the usual length on the inner. 



The rami of the third legs are large, well separated, and closely 

 approximated to the margin of the basal apron, the claw at the base of 

 the exopod being of medium size and rather blunt. 



The fourth legs are three-jointed, with four spines, one at the 

 extremity of the second joint and three at the tip, all well curved. 

 The first three are small and of approximately the same size, the fourth 

 (the inner terminal) one is nearly three times as long and toothed on 

 its outer margin. The two short terminal spines are edged along 

 either side with a pectinated membrane. There is also a short semi- 

 circular membrane with a sharply serrated margin projecting like an 

 epaulette over the base of each of these three spines. 



The fifth legs are so small as to be invisible dorsally. Total length 

 8-12 mm. Length of carapace 6.1 mm.; width of same 5.9 mm.; 

 length of genital segment 2 mm.; length of abdomen 1.2 mm.; length 

 of egg strings 11 mm. 



Color a uniform transparent horn color, often marked in older 

 individuals with numerous dendritic delineations of an ocher yellow. 

 A short time after death the copepod assumes an entire change of 

 color, becoming a deep rose red. This new color is disposed in den- 

 dritic delineations corresponding to those of the ocher }^ellow and in 

 all probability the yellow is changed into the red during dissolution 

 (curtus, shortened.) 



Male. — Carapace broad ovate, as wide as long, strongly narrowed 

 anteriorly. Posterior sinuses inclined toward the central axis; median 

 lobe wider than in the female; lateral lobes plump and well rounded. 

 Free segment as wide as the genital segment, but with the same spindle 

 shape as in the female. Genital segment orbicular with well-rounded 

 -ides and posterior margin, a trifle wider than long, with the fifth legs 

 showing prominently at the posterior corners. It is much smaller 

 than in the female, being only one-third the length of the carapace. 



The abdomen is a little longer than the genital segment, contracted 

 where it joins the latter, and considerably swollen at the center. Anal 

 laminae very large and foliaceous (tig. 112). 



Of the appendages the second antennae and second maxillipeds are 

 the only ones requiring special mention. 



