272 



the length of the 2nd segment; the anterior margin of the 4th segment 

 distally forms a small, finely denticulate lobe and the posterior margin 

 is also distally denticulate; the 5th segment is linear and equal to the 

 4th in length; the 6th segment is equal to the 5th and 4th together; the 

 finger-shaped 7th segment is about 2/3 the length of the 6th segment, its 

 surface covered with thin villi. 



The pleon is shorter than the pereon. The urosome is equal to the 

 last somite of the pleon in length. The two urosomites are about equal 

 in length but the last (geminate) divided by a barely perceptible groove 

 giving rise to a very short urosomite II and a much longer urosomite III; 

 the distal angles of the latter do not project backward. The rami of 

 uropods I are equal in length, equal to the basipodite in length, and 

 with coarsely denticulate margins. The exopodite of uropods II is slightly 

 longer than the endopodite and equal to the basipodite in length; its outer 

 and distal part of the inner margin are boldly denticulate and the side 

 of the endopodite facing it finely denticulate, while the inner margin of 

 the endopodite is smooth. The rami of uropods III are shorter than the 

 basipodite, whose length is twice its width; the sides of the rami facing 

 each other are finely denticulate while the opposite sides are smooth. The 

 telson is roundish-triangular, relatively large, and extends to the middle 

 of the basipodite of uropods III. 



Distribution: Widely distributed in the surface waters of the tropical 

 zone of the three oceans. It is found in the southern parts of the Atlantic 

 and Indian oceans up to 50° S. It is known from 40° N in the Pacific 

 Ocean to the southern Subtropical Convergence. 



11 11. Vibilia caeca Bulycheva, 1955 (Fig. Ill) 



Bulycheva, 1955: 1050; Vinogradov, 1956: 208. 

 Length of adult crustaceans up to 6 mm. 



The head is short, with a small rounded rostrum bent downward. 

 Eyes are absent. Antennae I are longer than the head and first three 

 somites of the pereon; the base is deeply thrust into the cephalic cap- 

 sule and is cylindrical; the length of the 1st segment is more than its 

 height; the flagellum is longer than the head and the first two somites 

 of the pereon, its height does not exceed the base, and it is proximally 

 cylindrical but distally flat and obliquely truncate; each of the two api- 

 cally situated rudimentary segments bears a few setae. Antennae II are 

 short, extend to the middle of antennae I, and four-segmented; the distal 

 segment is the longest and bears minute setae on the surface. The maxil- 

 lipeds have broad outer lobes which are rounded at the ends and have a 

 band of 14-20 spinules running parallel to the inner margin; the medial 

 lobe is small, with a roundly elevated or truncate apex. 

 225 The 2nd segment of pereopods I is 2/5 the length of the entire leg, its 



anterior margin proximally convex, the posterior margin straight, and the 



