309 



somewhat bulged, and the distal part of the anterior margin terminates 

 in an acute denticle not reaching the level of articulation of the claw; 

 the latter originates from the projection of the posterior distal part of the 

 segment and hence the notch between the denticle and the base of the 

 claw is anteriorly truncate; the claw is short, very deeply curved, with its 

 apex toward the middle of the notch, and does not extend to the anterior 

 denticle (in very large females the denticle may be less prominent and 

 the projection rounded). 



The urosome is short and somewhat longer than the last somite of the 

 pleon. The urosomites are equal in length but the last one narrower. The 

 uropods have broad basipodites, their length in females 2.5-3 times, in 

 males 3-4 times the width. The endopodites are highly broadened proxi- 

 mally; the exopodites are equal in length but very narrow and triquetrous. 

 The margins of the basipodites and rami are denticulate; the rami of 

 uropods I are about 1/3, of uropods III half the length of the basipodite. 



Distribution: Found in the Atlantic Ocean between 50° S and 50° N, 

 the tropical part of the Indian Ocean, and southwestern part (north of 

 the Subtropical Convergence) and eastern equatorial part of the Pacific 

 Ocean. 



4. Cystisoma longipes (Bovallius, 1886) (Fig. 124) 



Bovallius, 1886: 13 (Thaumatops); 1889: 47 (Thaumatops spec. A, 

 non B); Stebbing, 1888: 1327.— bovallii Woltereck, 1903: 457 (Thau- 

 matops); Stephensen, 1918: 59 (Thaumatops). — africanum Barnard, 

 1916: 287.— magna (non Woltereck, 1903); Shoemaker, 1945a: 233. 



Length of females up to 80 . mm; males are smaller. 



The head in females is spherical. Marginal denticles are numerous, 

 more so than in other species: 15-18, more often 16-17. The number of 

 marginal denticles on the left and right, as in other species, is sometimes 

 not equal. There are five-six pairs of ventral denticles; the anterior denticles 

 are very large, glandular, almost not differentiated from the denticles of 

 the arcuate rows. The mandibles bear two denticles: the large central one is 

 acute and slightly curved medially and the lateral denticle, though similar 

 to the central, is smaller and placed about midway between the central 

 denticle and the place of attachment of the mandible; a third denticle 

 sometimes occurs on the outer side (either as a tubercle as shown by 

 Stephensen or as a developed denticle, as in the specimen in our collection). 



Pereopods I-II have well-developed basal spines although these are 

 shorter than in C. pellucide. The 2nd segment of pereopods I is longer 

 than the rest of the leg and bears denticles on its anterior margin and in 

 the distal part of its posterior margin; the 4th segment is asymmetrical, 

 with a shortened anterior margin and an angular lobe posteriorly armed 

 with setae; the 5th segment is elongated, the process coarsely denticulate 

 and extends to the base of the claw; the 6th segment is anteriorly convex. 



