THE GENUS TOZEUMA 379 



Antennal scale with two small outer setae and nine inner and terminal setae ; with two 

 distal segments traceable. Inner margin with slight protuberance before first seta. 

 Endopod spine-like. 



Maxillule, endopod unsegmented with five spines. Maxilla, exopod with five setae ; 

 endopod unsegmented, with three inner lobes bearing setae; apex with three setae. 



Maxillipedes 1-3 each with endopod of four segments, and with apical setae of 

 segment 4 long and slender ; exopods with three apical setae ; exopod of maxillipede i 

 with one outer marginal seta, the other two with a pair of setae. 



No later stages of this species are known ; but I am indebted to Mr F. S. Russell for 

 permission to describe later larvae belonging to two distinct species of Tozeuma taken 

 in plankton from the Great Barrier Reef. One of these (species B.R. II) is represented 

 by a single specimen, and is evidently the same as that described by Kemp (1916, p. 400) 

 as the larva of T. armatiim. In view of the fact that several species are known from 

 Australian waters I do not feel justified in accepting so precise an identification. 



Tozeuma species B.R. I 



Of this form there are eight specimens apparently representing five stages, of which 

 the youngest is certainly stage III, and the oldest probably stage VIII. Stage VII is not 

 represented, and it is probable that there is also a ninth stage. 



Stage III (Figs. 71, 72). Length of rostrum 2 mm., body 5-6 mm. ; total length 

 7-6 mm. 



Rostrum with two small ventral spines, broadening at base over eyes, with a spine 

 on either side representing the supra-orbital spines. Abdominal somites very elongated ; 

 somite i with anterior projection overlapping carapace, but not produced, as in later 

 stages, into a spine. Somite 3 with an enormous posterior process ending in a pro- 

 curved hook; somites 5 and 6 with lateral spines. Anal spine absent. Telson large, 

 deeply hollowed, with small lateral spine ; spine 2 fused with angle of telson ; spine 3 

 reduced to a small seta. 



Peduncle of antennule segmented ; endopod represented by a small tubercle bearing 

 a seta. Antennal scale slender, unsegmented, with outer apical spine and thirteen setae; 

 endopod spine-like, about three-quarters length of scale. 



Exopods of maxillipedes 2 and 3 with eight and ten setae. 



Legs I and 2 rudimentary, leg i fairly large and biramous. 



Uropods with endopod rudimentary; exopod with nine setae. 



Stage IV (Figs. 73, 74). Length of rostrum 4-0 mm., body 7-4 mm. ; total length 

 11-4 mm. 



Rostrum with three small ventral spines. Carapace with large supra-orbital spines 

 and pterygostomial spines. Abdomen unchanged, but anterior overlapping part of 

 somite i with sharp ventral angle, and somite 5 with very small posterior dorsal spine. 

 Telson more deeply forked, with 8+8 small spines, of which three are on outer margin 

 and the fourth forms the point of the fork. 



