415 



4. Pereopods III shorter than pereopods V 5. 



— Pereopods III slightly longer than pereopods V 6. 



5. Distal margin of 5th segment of pereopods V of female besides 

 medial protuberance bears medial denticle; length of this segment 

 in male equals maximum Width 2. P. atlantica Guerin-Men. 



— Distal margin of 5th segment of pereopods V of female without 

 medial denticle; length of this segment in male more than width.. . 

 3. P. solitaria Guerin-Men. 



6. Width of 4th segment of pereopods V of female more than its length. 

 Medial protuberance of distal margin of 5th segment of pereopods V 

 of male with dentate apex; anterior, largest denticle separated from 

 rest by notch. Basipodite of uropods II of male distally broadened . . 

 7 P. pacifica Streets. 



— Width of 4th segment of pereopods V of female less than its length. 

 Medial protuberance of distal margin of 5th segment of pereopods V 

 of male with dentate apex; anterior denticle not separated from other 

 smaller ones. Basipodite of uropods II of male linear 7. 



7. Fifth segment of pereopods V of female almost rectangular, its pos- 

 terior proximal angle projects roundly along bulged margin of 4th 

 segment; length and width of 4th segment roughly equal. Maximum 

 width of 4th segment of pereopods V of male in proximal third. 

 First gills much shorter than half length of 2nd segment of pere- 

 opods rV 6. P. colletti Bov. 



— Fifth segment of pereopods V of female roughly triangular, posterior 

 proximal angle not projecting; length of 4th segment considerably 

 more than its width. Maximum width of 4th segment of pereopods V 

 of male in middle. First gills longer than half length of 2nd segment 

 of pereopods FV 8. P. bucephala Giles. 



1. Phronima sedentaria (Forskal, 1775) (Fig. 178) 



Forskal, 1775: 95 (Cancer); Schousboe, 1802: 11 (Gammarus); 

 Latreille, 1803: 291; Vosseler, 1901: 14; Shih, 1969: 10; 1971: 

 288. — cusios Risso, 1816: 121. — atlantica (non Guerin-Meneville, 

 1836); White, 1847: 91. — borneensis Bate, 1862: 318. — novaezealandiae 

 Powell, 1875: 284. — neozelanica Thomson and Chilton, 1886: 

 l50.—spinosaBo\SL\\ius, 1887a: 25; 1889: 310.— tenella Stehhing, 1888: 

 1354.— affinis Vosseler, 1901: 20; Pirlot, 1929: 112; Shih, 1969: 25. 

 339 The largest species of the genus. Adult females reach 25-42 mm, 



males 12 mm. 



Antennae II in males are two-segmented and short, especially in the 

 specimens from the Atlantic and eastern part of the Pacific Ocean. Pereon 

 somite VII is slightly longer than pleon somite I. Length of 4th segment 

 of pereopods V is more than its width (in females it is almost twice the 

 width); length of the 5th segment is more than its width; the posterior 



