i6 



DISCOVERY REPORTS 



marginal setae: one slender outer seta near end. Flagellum very long, segmented, with 

 a pair of small spines near base and on penultimate segment. Pleopods very small. 

 Uropods slender, the setose part of the exopod not much longer than the bare part 

 (1-3 :i)- 



Fig. 8. 5. conmtus. a, Acanthosoma i ; b, Acanthosoma 2 ; c, eye in side view ; 

 d, end of antennal scale in stage i. 



Acanthosoma 2 (Fig. 8 b, c). Length 4-2 mm. Rostrum i-6 mm. 



General form as in stage i . Lateral spine of somite 3 shorter and more slender than 

 the others, and that of somite 5 much the longest. Telson the same but more slender. 

 Antennal scale with very long apical spine; flagellum about as long as body without 

 telson. Pleopods variable, but may be very long. Maxillipede 3 very long, reaching 

 near end of antennule. 



Colour. The brown-orange colour of the Elaphocaris is lost, and the body is colourless, 

 except for a large patch of vermilion in the gastric region. 



Mastigopus I (Fig. 9 a, b). Length 4-8 mm. Rostrum 0-83 mm. 



Rostrum longer than segment i of antennule ; basal spine very small. Supraorbital 

 and hepatic spines small ; posterior dorsal spine minute. Dorsal organ present. 



Abdominal somites with small dorsal spines, of which the fourth is the longest, and 

 long pleural points somewhat procurved. The large hook-shaped pleural spine of 

 somite 5 is a striking character by which the species may be easily recognized. Telson 

 long and slender, more than three times as long as wide, and reaching to near end of 



