536 



— Body size rarely exceeding 2.5 cm. Telson broadly rounded at tip, 

 much shorter than uropods II. Females with two pairs of gills at base 

 of pereopods V-VI 3. 



2. Exopodites of uropods II-III rudimentary. Process of 5th segment 

 of pereopods I with additional tooth on posterior margin. Male with 



three pairs of gills at base of pereopods FV-VI 



I. R. armatum (M.-Edw.) 



— Exopodites of uropods II-III well developed; additional tooth on pro- 

 cess of 5th segment of pereopods I absent. Males with two pairs of 

 gills at base of pereopods V-VI 2.R. whitei Bate. 



3. Length of telson not less than half length of last urosomite, reaching 

 tips of uropods II A.R. minor Page. 



— Telson much shorter than half length of last urosomite, falling far 

 short of tips of uropods II 3. R. brevicaiidatum Stebb. 



1. Rhabdosoma armatum (Milne-Edwards, 1840) (Fig. 231) 



Milne-Edwards, 1840: 451 (Oxycephalus); Bovallius, 1890: 119 

 (Xiphocephalus); Spandl, 1927: 210; Pirlot, 1938: 374; Fage, 1960: 88; 

 Pillai, 1966: 196— sanzoi Cecchini, 1929: 12. 



Tshe actual size of the crustacean is difficult to measure since in 

 capturing, the tapered ends of the rostrum and telson break off. The 

 maximum size of sexually mature females reaches 152 mm, of males 

 80 mm. 



The rostrum is longer in females than in males, piliform, and tapered 

 toward the tip; the height of the middle part of the head, occupied by 

 the eyes, is almost equal to the height of the pereon. 



Pereopods I and II are very small and their 2nd segment is very 

 433 slightly shorter than the remaining segments together. In pereopods I 

 the structure of the chela is characteristic for the species: the maximum 

 width of the 5th segment is more than its length; the distal process is 

 large, its length half the posterior margin of the segment, and reaches the 

 base of the claw; the 6th segment is short, has a bulged anterior margin, 

 and the distal part of the posterior margin also forms a pointed trian- 

 gular process that does not reach the tip of the claw and is denticulate 

 on both sides. The 5th segment of pereopods II is somewhat elongated 

 and has a narrow distal process that almost reaches the tip of the claw 

 and is denticulate on the inner side; the 6th segment is elongated and its 

 distal process reaches almost the middle of the claw. The 4th segment 

 of pereopods III-IV is broader and longer than all the others and the 

 5th segment approximately half the length of the 4th. Pereopods V are 

 the longest; the 2nd segment is strong, linear, of the same width as the 

 4th but appreciably longer. Pereopods VI are much shorter than pair V; 

 the 2nd segment is barely broadened and the remaining segments vir- 

 gate. Pereopods VII are reduced, generally in the form of unsegmented 



