130 IIY/xoft New Species of Parasitic Copepods. 



Total length of female, 12 mm. ; width of carapace, 5.9 mm. Total length 

 of male, 7.6 mm. ; width of carapace, 3.1 mm. A grayish horn color, nearly 

 uniform throughout ; not quite as transparent as in gracilis. Very common 

 on the outside surface of the sand shark, and also frequently found on the 

 smooth dog-fish in company with the preceding species. 



(glabrum, smooth.) 



Nesippus alatus sp. nov. 



Type from Buzzards Bay, Massachusetts.* 



> Female. Carapace transversely elliptical, the width once and three- 

 quarters the length. Frontal plates distinct and, with a portion of the 

 cephalic area, projecting in a half circle from the anterior margin. Posterior 

 lobes short and wide ; thoracic area quadrilateral and raised a little above 

 the rest of the dorsal surface. Eye distinctly tripartite. Only the first thoracic 

 segment fused with the head, the others free. Second and third segments 

 fused inter se and carrying a single rectangular plate on either side. Fourth 

 segment free, considerably narrower than the first two and covered dorsal ly 

 with a pair of fused plates. These plates are much larger than in other 

 species, circular in outline, and they overlap the genital segment for some 

 little distance. Genital segment elliptical with evenly rounded outlines, the 

 length to the breadth in the proportion of 8 to 5. Abdomen very small, 

 triangular in shape, and attached about its own length in front of the poster 

 ior margin of the genital segment, on the ventral surface of the latter. It is 

 thus invisible in dorsal view, but the two large anal laminae show up for 

 their entire size. The appendages closely resemble those in N. orientalis 

 Heller, and N. crypturus Heller, with an impartial distribution of the simi 

 larity. Thus the first antennae are like those in both species; the second 

 pair show most resemblance to those of orientalis ; the second maxillae are 

 like those of crypturus; the first maxillipeds like orientalis, the second pair 

 most like crypturus. But in the present species the second maxillipeds are 

 much more massive than any heretofore described and approach closely 

 the condition seen in Pandarus. There are also sucking disks or pads at 

 the base of both pairs of antennae very similar to those in Pandarus. 



Male. Carapace semi-elliptical, a trifle wider than long, squarely trun 

 cated posteriorly, with a long and narrow lobe at each of the posterior 

 corners. Free thoracic segments of about the same length but diminishing 

 regularly in width, none of them fused and none carrying dorsal plates. 

 Genital segment small, a little narrower than the preceding segment and 

 of about the same length and width, with reentrant corners. Abdomen 

 very short, the basal joint scarcely visible beneath the posterior border of 

 the genital segment ; anal laminae no larger than in the female but with 

 much longer setae. 



Total length of female, 7 mm. ; width of carapace, 3.8 mm. Total length 

 of male, 4.55 mm. ; width of carapace, 2.3 mm. 



*The types of this species and the next will be eventually placed in the U. S. National 

 Museum. 



