GENUS OF TEKEESTKIAL ISOPODA. 439 



spread out of filling the space between the outer lobes when they are 

 separated laterally. 



The first maxilla is o£ normal shape, its narrow inner lobe bearing two 

 densely hairy bristles. 



The second maxilla is somewhat curved near the base, but the outer edge 

 is not angularly produced as in Onisciis, &c. 



The maxillipeds have the epipod large, flanking the basal part, and taper- 

 ing distally ; the second joint is broad, but not so much expanded as in 

 Oniscus ; the palp is longer than the masticatory lobe and shows indications 

 of the separate joints of which it is composed. 



The pleopoda are of the same type as those of the Oniscidse ; the inner 

 ramus of the second pair in the male is particularly long, terminating in a 

 very long slender lash. 



The uropoda vary in the different species and are described below ; they 

 are the same in the two sexes. 



Budde-Lund (1906) divided the genus into two subgenera with the 

 following characters : — 



Subgenus Deto i 



1. Antennae rather long and slender ; joints of flagellum fairly long. 



2. Palp of maxillipeds a little longer than the masticatory lobe. 



3. Endopod of uropod short, scarcely reaching to the middle of the 



exopod. 



Subgenus Vinneta : 



1. Antennae rather short, stout; joints of flagellum very short. 



2. Palp of maxillipeds much longer than the masticatory lobe. 



3. Endopod of uropod rather long, longer than exopod. 



Of these three characters the first two do not appear to me to be reliable 

 for subgeneric characters. It will be seen from the descriptions given below 

 that in most of the species the antennae differ considerably in the two sexes, 

 and that while the male may have the antenna very stout, in the female it 

 may be fairly slender, with the joints of the flagellum of moderate length. 

 Again, the palp of the maxillipeds is in all cases longer than the masticatory 

 lobes, and the differences in its length are not sufficient to be of much 

 importance. 



The third point seems, however, to be a good one and enables the species 

 at present known to be separated into two groups, one including the species 

 found in New Zealand and South America, and the other the species in 

 South Africa, St. Paul's (Indian Ocean), and Australia. 



Owing to the great differences between the male and the female, and the 

 fact that in this, as in many genera of the Isopoda and Amphipoda, the 

 females of the different species are nearly alike, it is hopeless to try to 

 distinguish between the species without making use of the characters of 



