96 THE VOYAGE OF H.M.S. CHALLENGER. 



Abdomen of the male (?) four-jointed. Anterior antennae twenty-three-jointed on the 

 ri^ht, twenty-four-jointed on the left side, very sparingly setose (figs. 11, 12), the joints 

 indistinct towards the base, the seventeenth and eighteenth joints of the right side are 

 longer than the neighbouring joints, and the eighteenth bears at its apex a not very long 

 and simple spine, but there is no distinct geniculation or serratures. The marginal 

 spines of the swimming feet (fig. 14) are simple, the terminal ones dagger-shaped and 

 minutely pectinated. The fifth pair of feet are simple, last branch three-jointed, 

 terminal joints bearing short marginal spines. 



This species, of which I have seen only two examples, was taken off Ascension Island 

 (Station 344). Except for the swollen and spiniferous right antenna, I should probably 

 have set them down as females, the characters of the fifth pair of feet being such as are 

 commonly found in that sex. There is an appearance of immaturity in the indistinct 

 jointing of the anterior antennae, but the size of the animal and the full development of 

 the swimming feet do not support that idea. On the whole it seems best to assign the 

 specimens a distinct specific name. 



10. Pontella securifer, n. sp. (PL XLV. figs. 1-9). 



Right anterior antenna (fig. 1) of the male very tumid in the middle (ninth, tenth, 

 and eleventh joints), the ninth ' bearing a long and stout spine, the twelfth a hatchet- 

 shaped process, its outer margin bordered with a serrated plate, thirteenth joint simple, 

 fourteenth with a marginal pectinated plate, last joint (fourteenth) very long and slender; 

 a geniculation between the twelfth and thirteenth joints. Inner branch of the first pair 

 of swimming feet three-jointed, — of the second, third, and fourth pairs two-jointed in 

 both sexes. Abdomen of the male three- (fig. 7), of the female (figs 8, 9) two-jointed, 

 very short, and curiously distorted. Rostrum and eyes (figs. 2, 3) as in Pontella strenua. 



I have seen only two or three specimens from a gathering made in Mid-Pacific, 

 August and September 1875. 



11. Pontella magna, Lubbock, 



Labidoeera magna, Lubbock, Ann. and Mag. Eat. Hist., ser. 2, vol. xi. (1853), p. 208, pi. x. 

 figs. 8-11. 



A few specimens occurred in a gathering from the South Atlantic (lat. 37° 38' S., 

 long. 39° 36' W.). Sir John Lubbock's specimen was also from the South Atlantic, lat. 

 18° 40' S., long. 2° 30' W, 



