259 



214 



Fig. 106. Vibilia robusta Bovallius (Us, Pj, Pn — after Stephensen, 191? 



215 



elongated, and intensely pigmented. The base of antennae I is short; the 

 1st segment of the flagellum is not longer than the head, with paral- 

 lel upper and lower margins, anteriorly rounded, and slightly inclined 

 ventrally; the 2nd segment of the flagellum is subapical and highly 

 reduced in large individuals and discernible only under a microscope; 

 the two reduced apical segments are quite distinct in individuals less 

 than 15 mm in length. Antennae II are not longer than antennae I and 

 seven- to eight-segmented. 



The pereon is equal in length to the pleon and urosome together. 

 Somite I of the pereon is half the length of somite II. Somites III-VI are 

 each slightly longer than somite II, while somite VII is equal to it. The 

 2nd segment of pereopods I is equal in length to the remaining segments 

 together, its margins uniformly convex, and its maximum width more 

 than half its length; the 4th segment is elongated along the posterior 

 margin; contrarily, the 5th segment is longer along the anterior margin, 

 the distal margin and the distal part of the posterior margin denticulate, 

 and the posterior distal angle bears a group of several adjacent chitinized 

 spines; the 6th segment is approximately the same length as the 5th and 

 has a convex anterior margin bearing several setae and a straight poste- 

 rior margin; the posterior and distal margins are denticulate; the claw is 



