284 



233 anterior margin (proximally convex, medially concave) and highly con- 

 vex posterior margin; the 4th and 5th segments are approximately equal 

 in length; the claw is 1/4 the length of the 6th segment. The 2nd segment 

 of pereopods FV has a straight anterior and convex posterior margin; in 

 all other aspects pereopods IV are identical to pereopods III; the pos- 

 terior margins of the 4th-6th segments are finely denticulate. Pereopods 

 V-VI are also identical except that pereopods V are slightly longer, the 

 4th-6th segments are linear and narrow, the 5th segment is armed with 

 spiniform setae, and the anterior margin of the 6th segment is serrate, 

 posterior is smooth. Pereopods VII extend to the end of the 5th segment 

 of pereopods VI; the 2nd segment is longer than wide, the posterior lobe 



234 quite broad, extending up to the base of the 4th segment; the 3rd-6th 

 segments gradually increase in length; the 7th segment is notably shorter 

 than the 6th and slightly shorter than the 5th. 



The pleon is equal in length to the last five somites of the pereon. The 

 urosome is equal in length to somites II and III of the pleon. Judging from 

 the lateral notches demarcating the fused urosomites II and III, urosomite 

 II is the shortest and urosomites I and III approximately identical. The 

 posterior lateral angles of the urosome are stretched backward, forming 

 round lobes. The basipodite of uropods I is distally denticulate on the 

 outer side and twice the length of the rami, which are equal in length; 

 the exopodite has large denticles on the outer side; the sides of the rami 

 facing each other are finely denticulate; the fine denticulation on the 

 inner margin of the endopodite is replaced by coarser denticles toward 

 the apex. The basipodite of uropods II is 1.5 times longer than the rami; 

 the exopodite has short sparse denticles on the outer side; the sides of 

 the rami facing each other are finely denticulate; the proximal part of the 

 inner margin of the endopodite is smooth. The basipodite of uropods III 

 is typically "pyriform" (in plane), i.e., it is extremely narrow proximally 

 and broadens distally (shence — pyripes), the maximum width being equal 

 to the length; the inner distal angle is stretched backward; the endopodite 

 is not distinctly denticulate along the outer margin and the inner margin 

 is smooth; the sides of the rami facing each other are finely denticulate. 

 Distinct sexual dimorphism is not seen in the structure of uropods III. The 

 telson is large, round, and its apex reaches the middle of the basipodite 

 of uropods III. 



Distribution: Found in both tropical and temperate waters of the 

 Atlantic Ocean but only tropical waters of the Indian Ocean. It is known 

 in the Pacific Ocean from the waters of southeastern Japan, the eastern 

 part of the tropical zone, and southward of New Zealand. 



235 16. Vibilia bovallii Bonnier, 1896 (Fig. 116) 



Bonnier, 1896: 612; Behning, 1912: 221. 



