306 



perfectly round pore is left between the claw and notch of the distal 

 margin; the apex of the claw leans toward the anterior side of the bulge 

 covering it and the maximum width of the segment occurs along the 

 distal margin. In males the 6th segment is narrow and equal to the 5th 

 segment. 



The urosome (with uropods) is somewhat shorter than the pleon. The 

 total length of the urosomites is equal to the length of the last somite 

 of the pleon; urosomite II is slightly shorter than urosomite I. The rami 

 of the uropods are equal in length and the basipodites are broad. The 

 basipodite in uropods I is three times longer than wide, its margins den- 

 ticulate; the rami are 1/4 the length of the basipodite; the endopodite is 

 proximally very broad and distally sharply constricted and acute, while 

 the exopodite is narrow. The basipodite of uropods III is distally broad- 

 ened, its length four times the maximum width; the ratio of length of 

 rami and basipodite is the same; the sides of the rami facing each other 

 are finely serrate while the opposite sides bear low denticles. 



Notes: Shoemaker (1945a) reported a find of 15 specimens of Cys- 

 tisoma in the region of the Bermuda islands, which he identified as 

 C. magna on the basis of Stephensen's (1918) and Barnard's (1932) 

 keys. However, from the morphological notes of the author, it appears 

 that an error has occurred in identification: as per the aforesaid keys, 

 the given specimens should have been related to the species C. longipes 

 which bears two spinules on each of the mandibles and up to 18 marginal 

 denticles. 



Distribution: Three reliable finds are known from the tropical part 

 of the Indian Ocean (two females, one male) and one from the southern 

 Atlantic (female). We obtained three adult females and one male — from 

 the eastern equatorial and north central (27°03'N 1 17°52'W) parts of the 

 Pacific Ocean. Thus the species may be considered as distributed in the 

 warm waters of these three oceans. 



251 3. Cystisoma fabricii Stebbing, 1888 (Fig. 123) 



Stebbing, 1888: 1333; Woltereck, 1903: 457 (Thaumatops); Step- 

 hensen, 1918: 63 (Thaumatops); Barnard, 1932: 272. — /oven/ Bovallius, 

 1889: 52 (Thaumatops).— coalita Woltereck, 1903: 457 (Thaumatops). 



Length of females up to 80 mm, of males rarely more than 50 mm. 



The head in females is slighdy longer than wide, the dorsal side 

 convex, the ventral side flat, slightly convex only in the region of the 

 ventral denticles. In males the head is short and high (in lateral view 

 almost wedge-shaped), obliquely truncate on the frontoventral plane, and 

 convex in the region of the ventral denticles. Antennae I in females are 

 shorter than the head, in males much longer; the antennal bases are con- 

 tiguous; the flagellum is triquetrous and has an acute apex. There are 

 12-16 marginal denticles while the ventral denticles only two pairs: the 



