no. 2354. NEW SPECIES OF PARASITIC COPEPODS— WILSON. 11 



parasitic copepocls, which have been published in previous papers 

 of this series.) 



BLAKEANUS CORNIGER, new species. 



Plate 5, figs. 39-^3. 



Host and record of specimens. — A single adult female with muti- 

 lated egg strings was taken from the Ascidian, " Cynthia carnea" in 

 Long Island Sound by the United States Bureau of Fisheries in 

 1874. It is made the type of the new genus and species with Cat. 

 No. 53569, U.S.N.M. 



/Specific characters of female. — Anterior body wide and very 

 strongly inflated dorsally; posterior body much narrower and 

 tapered. Head and first four thorax segments fused, with only a 

 partial furrow on the dorsal surface between the head and the first 

 segment. Dorsal inflation greatest in the fourth segment, where the 

 height or thickness is about equal to the length and breadth of the 

 entire inflation. 



Along the midline of the ventral surface of this cephalothorax is 

 a shallow longitudinal groove, bordered on either side by a low 

 ridge. This ridge is curved around the anterior end of the groove, 

 where it projects obliquely downward and forward. In the groove 

 are arranged in order the antennae, mouth parts, and four pairs of 

 swimming legs, packed closely together. At the posterior ventral 

 corners of the inflated portion are attached a pair of horns, which 

 extend out obliquely sidewise and backward. Each horn is curved 

 into the shape of the letter S and tapers from the base to the tip, 

 which is bluntly rounded. 



The fifth thorax segment is abruptly depressed to the level of the 

 genital segment on the dorsal surface, but is considerably extended 

 laterally to the bases of the horns. The groove of demarcation 

 between the fourth and fifth segments is not carried far enough 

 laterally to determine whether the horns belong exclusively to the 

 fifth segment or not, but the indications are that they do. 



The genital segment is cylindrical, two-fifths wider than long, 

 with a pair of small rounded projections close together on the mid- 

 line of the dorsal surface near the anterior margin. Through the 

 tips of these projections the oviducts open into the external egg sacks. 

 The latter are club shaped and considerably swollen posteriorly, 

 and they project a quarter of their length beyond the tip of the 

 abdomen. The eggs are comparatively large and are not arranged 

 regularly in rows. There are about 75 or 80 in each sack. 



The abdomen is four jointed, the joints distinctly separated and 

 diminishing slightly in width backward ; the first, third, and fourth 

 joints are about the same length, the second is somewhat longer. At 

 the tip of the terminal joint are the anal laminae, which are flattened 

 laterally and curved up dorsally; they are entirely destitute of setae. 



