322 



DISCOVERY REPORTS 



Telson nearly four times as long as wide with four large widely spaced lateral spines ; 

 distal margin produced, with four spines on either side of the very large median spine ; 



spine formula 8, i, 8. 



Eye oval. Antenna: basis with small inner spine; scale with outer basal seta. Maxil- 

 lule with palp of two segments ; maxilla with small basal segment distinct, the rest not 

 distinctly segmented. Maxillipede i with outer seta on segment i. 



Chelae of leg i stout. Leg 5 with vestigial exopod. Epipods absent. Four pairs of 



pleopods. 



A specimen from St. 1576 very closely resembles this species, but differs in several 

 details. The dorsal spines are smaller; the proportional length of the spines of the 



Fig. 22. Thalassinid D. XII. St. 1576. 

 a. Abdomen. b. Rostrum. 



c. Telson. d. Chela, leg i. 



telson is not the same, and the chela of leg i is much stouter. There is also no seta on 

 the antennal scale. 



Two specimens from St. 1580 cannot be distinguished from the form described 

 except that there is no trace of an exopod on leg 5. 



Thalassinid B.R. IV 



Barrier Reef St. 50. 



Rostrum 1-75 mm. ; body 5-95 mm. 



Rostrum broad, tapering, much longer than antennule. Carapace with seven small 

 marginal spines. Abdomen: somite 2 with very large hollowed spine; somites 3-5 with 

 small spines and slight ridge. Pleura rounded. 



Telson three times as long as wide, parallel-sided ; posterior margin convex, with very 

 long median spine; spine formula 8, i, 8. 



