Wilson New Species of Parasitic Copepods. 131 



Color of female a light yellowish white, fairly transparent, the egg-strings 

 almost pure white. The male is darker in color and usually becomes 

 brown in preservatives. 



The females of this species are found upon the gill arches of the common 

 sand-shark, rarely on the floor or roof of the mouth. The male is found 

 on the outside surface of the body in company with both sexes of the pre 

 ceding species. It can not be regarded as abundant since it is rare to find 

 more than one female on the same fish, but it is fairly common. 



(alatus, furnished with wings.) 



Eudactylina nigra sp. nov. 



Type from Buzzards Bay, Massachusetts. 



Fe ni' tie. Body elongated, largest at the anterior end and tapering regu 

 larly to a blunt point at the posterior end. The six free thoracic segments 

 diminish regularly in width but are of very different lengths, the first one 

 being the shortest, and the fifth one the longest. The carapace covers the 

 head and projects more or less over the first free segment, sometimes nearly 

 hiding it in dorsal view. It is of about the same length and width, with 

 rounded corners and a deeply emarginate posterior border ; the sides also 

 are often more or less emarginate. 



The first antennae are very prominent at the anterior margin, and their 

 basal joints appear like the frontal plates in the Callgidae. Both pairs of 

 maxillipeds project beyond the lateral margin of the carapace and stand 

 out prominently in a dorsal view. Each of the first four thorax segments 

 carries a pair of biramous swimming legs; on the last two segments the legs 

 are rudimentary and consist of a basal joint only, without rami. On the 

 sixth segment they can be seen plainly only on immature females and ap 

 parently disappear in the adult. 



The egg-sacks are attached to the sides of the sixth (genital) segment ; 

 each is fully as wide as the genital segment, considerably more than half as 

 long as the entire body, and contains from eight to twelve eggs. The 

 abdomen is very small and two-jointed, with minute anal laminae. Of 

 the appendages, the second maxillae differ from those in other species by 

 being much longer and more slender, and are plumose for their entire 

 length. The second maxillipeds also are larger than in any described 

 species, and stand out more prominently in dorsal view. These two par 

 ticulars will at once distinguish the present species from all others. 



Total length, 2.4 mm.; length of carapace, 0.5 mm.; width of carapace, 

 0.4 mm.; length of egg-strings, 1.3 mm. 



General color a dark brown or black, the brown shade due to the two 

 long and irregular ovaries, the black to the contents of the intestine. The 

 eggs are very large and also dark brown in color, so that the living copepod 

 shows well against the red background of the gills. 



This species is found abundantly on the gills of the sand shark, being 

 firmly fastened by its second maxillipeds to the gill filaments. Many 

 hundreds may often be secured from a single shark. 



(nigra, black.) 



