REPORT ON THE OSTRACODA. 



165 



intervals of which are often finely punctate. The shell of the male (PI. XLI. fig. 11) is 

 smaller, broader in proportion to its length, and the anterior rostriform process is short 

 and obtuse. The margins of the valves at the posterior ventral angle show often a 

 series of minute, irregular serratures (PL XL. fig. 3). The setse of the anterior antennae 

 in the female (fig. 6) are one long and three short, in the male (fig. 5), one short and 

 three long, the latter being anuulated and densely setose ; one of the three beai's also a 

 series of very delicate marginal loop-like appendages (fig. 5, a). The secondary branch 

 of the posterior antennae has the basal joint very much dilated and bearing two short 

 setse, while the last joint in the female (fig. 7) has five or six long subequal, densely- 

 ciliated setae, and in the male (fig. 8) a strongly hooked claw and three setae, two of 

 which are long and one short. Length, 1-1 5th of an inch (l"6 mm.). 



The following is a list of the localities of the tow-net gatherings in which Halo- 

 cypris atlantica was found ; in some of these cases it was scarce, but in others very 

 abundant : — 



Following these references on the map, the very wide distribution of this species 

 becomes at once aj)parent, the points indicated being spread over the Pacific Ocean from 

 10° south of the Australian continent to the latitude of Japan in the north, and to 

 Patagonia in the east, while in the Atlantic it occurs from the latitude of Patagonia 

 southward to that of Sierra Leone in the north, this last being also the district 

 in which Sir John Lubbock's type-specimens were taken. If Dr Glaus' Messina 

 specimens be taken to belong to the same species, its range will, of course, extend to 

 the Mediterranean. 



[PL XL. figs. 1-15. 1 Carapace of female seen from left side, 2 from above (both 

 magnified 35 diameters), 3 portion of margin of shell more highly magnified, 4 

 anterior antennae of male with tentacle, 5 one of the same more highly magnified, 5a 

 portion of central seta showing marginal loops, 6 anterior antenna of female, 7 posterior 

 antenna of female, 8 secondary branch of posterior antenna of male, 9 mandible and paljj, 

 10 first maxilla, 11 second maxilla, 12 first foot of female, 13 first foot of male, 14 



