316 



258 Distribution: Tropical and subtropical waters of the three oceans; it 



does not occur beyond the limits of the Subtropical Convergences. It has 

 also been recorded from the eastern part of the Mediterranean Sea. It is 

 found up to a depth of 500 m, rarely deeper, and possibly undergoes in 

 diurnal vertical migrations (Brusca, 1967a). 



Reproduction probably takes at the end of the summer, in autumn, 

 when the sex ratio in the population equalizes and the greatest number 

 of females with eggs is found. The pereon of the egg-bearing females is 

 usually highly bulged and the brood chamber well noticeable in a lateral 

 view because not covered by the coxal plates. 



2. Paraphronima crassipes Claus, 1879 (Fig. 127) 



Claus, 1879: 65; Bovallius, 1889: 33; Vosseler, 1901: 97; Chevreux 

 and Page, 1925: 390; Spandl, 1927: 166; Pillai, 1966: 2\Q>.—clypeata 

 Bovallius, 1885b: 11; 1889: 33.— pecr/nato Bovallius, 1885b: \?>.—cuivis 

 Stebbing, 1888: 1337. 



Adult females may reach 31 mm and males 24 mm; the usual size 

 is up to 24 and 20 mm respectively. 



The head is very large, but as the body is more massive than in 

 P. gracilis, the disproportion between size of head and body is less con- 

 spicuous. The head is slightly more in»length than in height but does not 

 exceed the total length of somites I-IV of the pereon. The head in males 



Fig. 127. Paraphronima crassipes Claus (°, Us — after Chevreux and Fage, 1925; Mx,-,, 

 Mxp, Md— after Bovallius. 1889; P,-„, VII— after Pillai, 1966). 



