LARVAE OF DECAPOD CRUSTACEA 327 



posterior margin slightly concave, with long median spine and four spines either side ; 

 spine formula 8, 1,8. 



Eye rather pointed, black. Antenna : basis with inner spine ; scale with long outer 

 basal seta. Palp of maxillule and maxilla of three segments. Maxillipede i with outer 

 seta on segment i. 



Chela of leg i large, dactyl longer than palm. Leg 5 without exopod. Epipods absent. 

 Three pairs of pleopods. 



Callianassa? B.R. VIII (Fig. 28) 



Barrier Reef St. 44. 



Rostrum 1-35 mm.; body 4-85 mm. 



Rostrum rather broad, nearly parallel-sided. Carapace with small close-set spines 

 in front. Abdomen : somite 2 with enormous dorsal spine curving over somite 3 and 

 reaching middle of somite 4 ; somites 3-5 with high smooth ridge. Pleura rounded. 



Fig. 28. Thalassinid B.R. VIII. 

 a. Side view. b. Telson. 



Telson: length about i\ times width; lateral spines widely spaced; posterior margin 

 slightly concave. 



Eye rather pointed, black. Antennal scale with long basal seta on outer edge. Palp 

 of maxillule and maxilla of three segments. Maxillipede i with outer seta on segment i ; 

 epipod a small papilla. 



Chelae of legs i and 2 not fully formed. Leg 5 without exopod. Epipods absent. 

 Three pairs of pleopods. 



Group II D 

 Telson of C II type 



Callianassa? D. XVII (Fig. 29) 

 Discovery St, 406. 



Rostrum 1-25 mm. ; body 5-85 mm. 



Rostrum rather narrow, little longer than antennule. Carapace with nine 

 marginal spines. Abdomen : somite 2 with long dorsal spine as long as somite 3 ; 



