LARVAE OF SERGESTES 



23 



and longer than exopod ; exopod seven times as long as wide, the bare margin a little 

 longer than setose part. 



Colour. Bright red in thorax and throughout abdomen, and in arms of telson. Tips 

 of rostrum, antennal scale, flagellum and uropods red. Setae of uropod yellow. 



Acanthosoma 2. Length 5 mm. Rostrum 1-41 mm. 



Mastigopus. The slender elongated form of the thorax is a very striking characteristic 

 of this species and is shown in Bate's figures of S. junceus and S. longicollus, which are 

 young Mastigopus stages. 



We have only two specimens from Bermuda, of 6-5 and 7-8 mm. respectively, the 

 former probably in stage i . The latter was obtained by moult, but the moulted skin is 

 too damaged to be of use in determining the stage, though it is believed to be stage i. 



Fig. 14. S. temiiremis. a, Acanthosoma i, head of specimen mouhed from Elaphocaris; 

 b, Mastigopus 2 ? 7-8 mm. ; c, telson. 



Mastigopus 2 (?) (Fig. 14 b, c). Length 7-88 mm. 



Rostrum very short, with strong basal tooth. Supraorbital spines present, but no 

 hepatic. Abdomen without dorsal spines, but with small pleural points on each 

 somite. Telson with deep median incision, each arm with one outer and two inner 

 spines. 



Eye less than one-seventh length of body (i : 7-57), its length twice the greatest 

 diameter of eyeball. There is a very small papilla on anterior face of stalk. Segments 

 2 and 3 of antennule equal. Antennal flagellum longer than body, without kink, but 

 with curved setae in distal half. Mandibular palp present, unsegmented. Legs 4 and 5 

 very small, rudimentary. Pleopods long; i and 2 without endopod, 3 with non-setose 

 endopod and 4 and 5 with setose endopods. Exopod of uropod six times as long as 

 wide, the bare part considerably longer than the setose part (i : 0-71). 



