NO. 1404. PARASITIC COPEPODS—CALIGIDM— WILSON. 613 



and the antennte curves forward and projects considerably, looking 

 like the stumps of an accessory pair of antennae. 



Posterior antenna; small, with a stout basal joint and a long slender 

 terminal hook, not bent very sharph'. They are situated far forward 

 almost at the ver}^ anterior margin of the carapace. No trace could 

 ])e found of the first maxilla? or the furca after the most careful search. 



Second maxillai short and wide, triangular in outline with swollen 

 bases, and blunth" rounded at the tip. They are closely appressed to 

 the side of the mouth tube and are about two-thirds its length. The 

 mouth tube is short and wide, almost a semicircle in outline, and 

 flattened against the ventral surface of the carapace. It does not seem 

 capable of being raised any distance from the latter as in Caligus and 

 other genera. 



First maxillipeds short and comparatively stout, the two joints 

 about the same length; terminal claws short and stout, the inner one 

 twice as long as the outer. Second maxillipeds greatly enlarged and 

 very strong, evident!}' serving as the principal organs of attachment 

 to its host. The basal joint is much swollen and furnished with power- 

 ful muscles; the terminal claAV is two-thirds as long as the basal joint 

 and strongly curved. No accessor}" spine could be seen upon the 

 specimens examined. 



The first thoracic legs are long and narrow, the second joint five 

 times as long as wide and cylindrical. The terminal joint is also much 

 longer than wide, and armed as in Callgus^ with three terminal claws 

 of moderate length, three plumose setfe on the posterior margin, and 

 a long slender seta at the corner between the two. Second legs large, 

 with a long basal joint and a three-jointed endopod and exopod, the 

 joints of similar size and shape, and armed with spines and plumose 

 sette, as in Caligus. Third legs also large, the rami close together, 

 each two-jointed and furnished with the usual number of plumose 

 setfc. The spine at the base of the exopod is of medium size and acu- 

 minate. Outside of the exopod on the margin of the apron is a wide 

 transparent flap, similar to that around the edge of the carapace, and 

 supported by numerous wavy hair-like ribs. Fourth legs short and 

 stout, two-jointed, the joints about equal. The terminal joint carries 

 three terminal spines and one on the outer margin, all nearly the same 

 size. No trace of the fifth legs can be found. 



Total length, 23.5 mm. Length of carapace, 1.1 mm.; width of 

 same, 1 mm. ; length of free segment, 14 mm. ; length of genital seg- 

 ment, 3.1 nun.; length of aVxlomen, 5.5 mm.; length of ^gg strings, 

 6 mm. 



Color of the carapace, a light yellowish brown, of the long neck- 

 like free segment a dark brown, of the genital segment a sulphur 

 yellow except in the posterior areas of the dorsal surface outside the 

 ridges, where the yellow is mixed with dark brown; color of the abdo- 



