no. 1758. ON MARINE COPEPODA AND CLADOCERA. SIIARPE. 423 



Remarks. — The members of this group seem so very distinct from 

 other known Ilarpacticoids as to merit the formation of this family. 

 At present, the characters of the genus Ilyopsyllus are those of the 

 family. Brady (1880, p. 145) was unable to find any evidences of 

 fifth feet, therefore this is omitted from the original description of 

 this genus. 



Genus ILYOPSYLLUS Brady and Robertson, 1873. 



ILYOPSYLLUS SARSI, new species. 



Length of female exclusive of caudal setae, 0.5 mm. Male unknown. 

 Color deep blood red. 



Seen from the side (fig. 186) the ventral line is nearly straight, 

 while the cephalic region is veryunusually arched. First segment of the 



Fig. IS.— Ilyopsyllus sarsi. a, mandibular palp, x 250; b, lateral 



VIEW OF FEMALE X 70; c, MAXILIIPEDS X 250; (I, ROSTRUM X 250; e, 

 FIFTH FOOT OF FEMALE;/, FIRST FOOT OF FEMALE X 250; (/, FURCAL RAMI 

 OF FEMALE X 250; h, SECOND ANTENNA OF FEMALE X 250; /, FIRST 

 ANTENNA OF FEMALE ■ 250. 



cephalothorax about one-half length of body. Abdominal segments 

 armed posteriorly with a row of small spinules, with one or two larger 

 spines at the outer angles. Rostrum (liii;. I8d) large, triangular, and 

 armed at tip with two movable spines. First antenna (fi<j:. I8i) six- 

 segmented, the first segmenl very large and with a semicircular row 

 of spinules at its inner distal angle. Second segment very short, and 

 produced into a broad, blunt, somewhat beak-like process, which is 

 fully as long as the third segment. Third segmenl slightly longer 

 than broad, and bearing a very long sesthetask, which is supported 

 on a two-segmented base, and is about twice as long as the four last 

 segments of the antenna taken together. Fourth and fifth segments 

 small, about as wide as long, terminal segment slightly longer and 

 bearing: a number of setae. 



