
NICHOLLS—COPEPODA FROM SOUTH AUSTRALIA 9 
antennae extend to the posterior margin of the genital segment. The fifth legs 
are very like those of salinus, as illustrated by Thompson & Scott (1908, pl. ii, fig. 
21) but the basal segment of the 2-segmented exopod (there is no endopod) is more 
elongate and has the inner distal corner extended into a triangular projection. The 
outer of the two large terminal spines has the small middle spine fused with it at 
the base. 

Fig. 3. Pseudodiaptomus cornutus sp, nov. Male and female X 57; appendages X 171. 
Male. Length 0-93 — 1:04 mm. Body as in the female but the dorsolateral 
knobs on the first segment are less pronounced when seen in lateral view than in 
the female. The urosome is 5-segmented and the caudal rami are similar to those 
of the female. The right first antenna is composed of 18 segments and reaches 
to the posterior margin of the second segment of the urosome. The fifth legs in 
the extended position reach to the middle of the fourth segment of the urosome. 
These legs show certain differences in proportions and armature from those of 
salinus, as shown by Thompson & Scott (op. cit. pl. ii, fig. 22). The coxa of the 
right leg bears two bifid spines set on small prominences at its inner distal corner, 
not shown for salinus, and the right endopod has the outer lamelliform plate wider 
than in Giesbrecht’s species. The terminal segment of this exopod is here modi- 
fied into a long curved claw reaching beyond the end of the left leg. The distal 
segment of the left exopod is more slender than in salinus and has a rounded 
