LARVAE OF SERGESTES 



6i 



Eye about one-fifth length of body; eyeball asymmetrical, the greatest width nearly 

 equal to total length, without papilla. Labral spine present. Antennal scale eight times 

 as long as wide ; flagellum more than twice length of antennule. Mandible without palp. 

 Exopod of uropod narrow, seven times as long as wide, the setose margin more than 

 1 1 times length of bare part. 



Acanthosoma 2. The only specimen of this stage taken moulted to Mastigopus, and 

 the cast skin is not sufficiently complete for description. The telson differs from the 



Fig. 53. S. armatus. a, Elaphocaris 3, 

 cast skin ; b, telson. 



Fig. 54. S. armatus. Acanthosoma i. 



specimen of stage i described in having a pair of very small dorso-lateral spines, and 

 the arms of the fork smooth. Exopod of uropod setose part of margin i-8 times as long 

 as bare part. 



Colour (stage i). Antennules dark grey at end. Flagellum of antenna orange red at 

 end. Thorax and eye with red markings as shown in Fig. 54. Abdomen colourless. 



Mastigopus I. Length 3-2 mm. Rostrum 0-38 mm. 



Carapace with small hepatic and posterior dorsal spines but no trace of lateral spmes. 

 Abdominal somites with dorsal spines, very small on somites i and 2, longest on 4. 



