296 DISCOVERY REPORTS 



The second to eighth thoracic segments are visible as narrow encircling folds of the 

 integument ; on none of them are the buds of the limbs free. 



The abdomen is of seven segments, longer than the carapace. The posterior lateral 

 margins of the sixth somite are produced backv^^ards into a pair of short spines ; as in 

 E. triacontha and E. longirostris these spines persist throughout the later Furcilia stages 

 but disappear before the adult form is reached. The telson is longer than the fourth to 

 sixth segments of the abdomen and strongly expanded distally. Its posterior margin is 

 emarginate ; the spines are as in the second Calyptopis. 



A fifth third Calyptopis occurred which I believe to be E. spinifera despite the strong 

 differences between it and those described above (Fig. 40 c). It is much smaller than 

 they are, only 2-5 mm. long, and differed from them in that (i) the dorsal organ is small, 

 (ii) the front part of the carapace is much narrower than the posterior and not expanded 

 widely over each eye, so that the narrow anterior margin is only faintly emarginate. 



I separate this specimen from the other four with greater confidence than these dif- 

 ferences would give me because what appear to be two corresponding kinds of the first 

 Furcilia stage occur (see below). It occurred in a net haul which included one of the 

 four specimens of the third Calyptopis described above, one of each of the two kinds of 

 the first Furcilia stage described below, later Furcilia stages and adults, of E. spinifera. 



Furcilia, stage I (Fig. 40 d) 

 Description based on the examination of seven specimens, 4-0-4-2 mm. long. 



In this stage there is one pair of non-setose pleopods. 



The carapace has a high conical dorsal organ. The frontal plate is wide with broadly 

 rounded corners and an emarginate anterior margin; the entire margin is beset with 

 denticles, the lateral pointing slightly forwards, the anterior inwards. The only part of 

 the lateral margin of the carapace which is denticulate is that along and immediately 

 posterior to the antero-lateral spines. The posterior limit of the denticles is the point 

 where the carapace broadens out into a postero-lateral wing, a point which corresponds 

 with the constriction in the carapace in the third Calyptopis. The posterior projection 

 of the carapace is longer than in the previous stage. 



The antennular spine is longer than the sum of the second and third peduncular seg- 

 ments ; it is wide with a small number of strong spines along its inner margin (omitted 

 from the figure). The flagella are unsegmented. 



Buds of the second thoracic limbs only are free ; they are large. 



Beginnings of the tergal wings of the first abdominal somite are present, standing 

 strongly out with their distal ends curved forwards and downwards. There is a small 

 median posterior spine on the third somite but not on the fourth or fifth. The hinder 

 lower edges of the pleura are not denticulate. The telson is similar to that of the previous 

 stage. 



