no. 1404. PARASITIC COPEPODS—CALIGIDJE— WILSON. 569 



good size, terminated by one short and three long plumose setae, the 

 longest about three times the length of the laminae. 



First antennae large, their tips nearly equaling the extreme width 

 of the carapace; terminal segment about the same length as the basal, 

 one-quarter as wide as long. 



Second antennae close together and rather weak, with a small sup- 

 plementally hook on the posterior margin of the basal joint. Mouth 

 with a somewhat quadrilateral opening fringed by long setas; margin 

 of the upper lip incised at the center; mandibles stout, strongly 

 curved, and toothed along their inner border. 



First maxillae small, short, and slightly curved; second maxillae 

 slender, nearly straight, and acuminate. 



First maxillipeds with a very slender terminal joint about half as 

 long again as the basal joint, the two curved claws at the tip very 

 unequal. Second maxillipeds fairly stout, the basal joint and the ter- 

 minal claw of about the same length, the latter with a small curved 

 spine on its inner margin. 



Of the swimming legs the first pair is three-jointed; the basal joint 

 is swollen and armed with two spines on its outer margin, and a chitin 

 plate carrying a spine on its posterior margin. 



The plate is transversely elongated and has a large blunt projection 

 near its distal end. 



The fourth swimming legs are three- jointed; the triangular second 

 joint terminates externally in a long spine; the terminal joint has a 

 stout spine on its external margin, and three long and one short (the 

 inner) spine at the tip. 



Total length 5-7 mm. Length of carapace 2.6-3.6 mm.; length of 

 genital segment 1.5-2.2 mm.; width of carapace 2.4-3.4 mm.; length 

 of abdomen 1-1.5 mm.; length of egg-strings 2.6-3 mm. 



Male. — Carapace about as broad as long and relatively wider ante- 

 riority than in the female; the posterior sinuses are also much wider 

 and their sides are flaring instead of parallel. The thoracic area is 

 only one-third the width of the carapace, and it scarcely projects pos- 

 teriorly at all; the lobes are much wider than those of the female and 

 ;irc well rounded. The free thoracic segment is considerabty longer 

 and narrower than in the female, while the genital segment is pear- 

 shaped, only one-third the width of the carapace and well rounded 

 posteriorly. The abdomen is about the same length as the genital 

 segment, two-jointed, with the first joint one-third as long as the 

 second (fig. so). 



The anal laminae are long and large, and are attached to the outer 

 posterior corners of the abdomen; the plumose seta 1 are fully twice as 

 long as in the female. 



On the ventral surface the second antenna 1 and second maxillipeds 

 are stouter than in the female, and the small spine on the side of the 



