DEVELOPMENT OF E. LONGIROSTRIS 293 



Furcilia, stage VII (Fig. 39 k, I) 



Only one specimen was found, 8-5 mm. long. 



In this stage there is one terminal spine on the telson. 



The dorsal organ is a low crest. The frontal plate and rostral spine are much as in the 

 previous stage ; the posterior projection of the carapace is shorter, reaching only to the 

 end of the first abdominal somite. 



The antennular spine reaches some way up the third segment of the peduncle ; be- 

 ginnings of the lappet of the first segment and of the carina of the third are present. The 

 mandibular palp is long, of three segments and setose. 



The thoracic limbs are as follows: 



First limb. Endopod long and kneed. No gill bud. 



Second to fifth limbs. Endopods long and kneed. Gills of three branches. 



Sixth limb. Endopod very much shorter than that of the anterior limbs but kneed. 

 A gill of three branches. 



Seventh limb. A gill of four branches and a number of small buds. 



Eighth limb. A gill of two small branches and smaller buds. 



The third abdominal somite is still the only one to have a median posterior spine ; it is 

 shorter than the fourth segment (Fig. 39 /). The pair of postero-lateral spines of the 

 sixth segment which appeared in the third Calyptopis stage are still present though very 

 short. The telson is very narrow ; there are three pairs of lateral spines along its distal 



half 



Post-Larval Stages 



Twenty-six specimens were found of which ten were closely, and sixteen more superficially, 

 examined. 



(i) With carapace retaining a long posterior projection. 



The posterior projection of the carapace is longer in all the larval stages of this species 

 than in the corresponding stages of E. spinifera, and the earliest post-larval stages, 

 unlike those oi E. spinifera, retain it. Three specimens were found, 97, 10 and 11 mm. 

 long. 



The frontal plate is reduced compared with that of the later Furcilia stages, but its 

 lateral margins are still nearly parallel at the base ; anteriorly they run obliquely forwards 

 to the rostral spine giving the front half of the plate a triangular shape. The margins are 

 denticulate. The rostral spine reaches from nearly to the end, to beyond the end, of the 

 second segment of the antennular peduncle. The posterior projection of the carapace is 

 as long as or longer than the first abdominal somite. 



The antennular spine reaches halfway or nearly halfway up the third segment of the 

 peduncle ; the lappet of the first segment is strong but not yet bifid ; there is no spine 

 from near the outer distal corner of the second segment ; the dorsal carina of the third 

 is beginning to develop. 



The spine of the third abdominal somite is nearly as long as the fourth ; very small 



