430 



1. Genus Phrosina Risso, 1822 



Risso, 1822: 244; Stebbing, 1888: 1424; Bovallius, 1889: 421; Chevreux 

 and Page, 1925: 413; Spandl, 1927: 168; Bowman and Gruner, 1973: 39. 

 — dactylocera Latreille, 1829. 



The head is high and tapered ventrally. The rostrum is very short, 

 in the form of two acute horns originating from the frontodorsal part of 

 the head Antennae I in females are very short; antennae II are absent. 

 The dorsal side of the body is without acute projections. The first two 

 pereon somites are fused. Pereopods I-II are simple; pereopods III-VI 

 have subchelae, their 6th segment is long, clawlike, while the 7th segment 

 (claw) is greatly reduced, often not at all perceptible. The 2nd segment of 

 pereopods VII is broadened leaflike and the distal part of the extremity 

 reduced. 



The pleon is shorter than the pereon, with massive high somites, the 

 last of which is the longest. The posterior distal angles of the epimeral 

 plates are strongly pointed and in somite III are considerably stretched 

 backward. The urosomites are very short and together the same length as 

 somite III of the pleon. The basipodites of the uropods are basally close- 

 set, broadly oval, or with a broader distal part. The telson is rounded 

 at the tip, its width at the base almost equal to the width of the distal 

 margin of the last urosomite. 



Type species: Phrosina semilunata Risso, 1822. 



The genus is monotypic. 



1. Phrosina semilunata Risso, 1822 (Fig. 187) 



Risso, 1822: 245; Stebbing, 1888: 1425; Bovallius, 1889: 426; 

 Vosseler, 1901: 89; Chevreux and Page, 1925: 413; Spandl, 1927: 168; 

 Pillai, 1966: 219.— pacifica Stebbing, 1888: 1430.— australis Stebbing, 

 1888: 1431. 



Size of females up to 30 mm, average about 10 mm; males are 

 smaller. 



The head is dorsally bulged and equal in length to somites I-III of 

 the pereon. antennae I are attached directly under the rostrum and in 

 females are not longer than the rostrum, in males longer. Antennae II 

 are developed only in males and may be longer than antennae I; they 

 are attached to the anterior part of the head at 1/3 the distance from its 

 lower margin. 



The pereon is almost the same length as the pleon and urosome 

 together. The boundary of fusion of somites I-II of the pereon is per- 

 ceptible as a faint groove. Pereopods I-II are simialar; pereopods II are 

 somewhat longer, their segments neither broadened nor armed; the 2nd 

 segment of both pairs of pereopods is longer than the rest together. 

 The 2nd segment of pereopods III is as long as the 3rd-5th segments 



