298 DISCOVERY REPORTS 



Four Other first Furcilia occurred which I beheve to be E. spinifera (Fig. 40 e). They 

 differ from those described above in the following ways : 



(i) They are smaller: 3-0, 3-1, 3-3 and 3-5 mm. long. 



(ii) The dorsal organ is inconspicuous or absent. 



(iii) The frontal plate is proportionately smaller and narrower than the carapace and 

 its anterior margin is nearly straight. 



(iv) There are no denticulations on the lateral margins of the carapace by the antero- 

 lateral spines. 



(v) There is no spine on the third abdominal somite. 



They occurred in three separate net hauls which contained, as well, other larval stages 

 and adults of E. spinifera. They are certainly the same species as the third Calyptopis 

 (Fig. 40 c) described from one specimen at the end of the last section : the frontal plate 

 is very similar. If they are E. spinifera then there are in that species two kinds of the 

 third Calyptopis and of the first Furcilia stage, the larger kind of one stage corresponding 

 in structure with the larger of the other, the smaller with the smaller. I have not found 

 two corresponding kinds of larvae in the succeeding stages, but the numbers of speci- 

 mens found and examined were very small. 



Furcilia, stage II 



Description based on two specimens, 5-0 and 5-1 mm. long. 



In this stage there are one pair of setose and three pairs of non-setose pleopods. 



The dorsal organ is very high. The frontal plate is not so expanded over the eyes as 

 in the first Furcilia: it is narrower and its lateral margins are nearly parallel. It has 

 rounded corners, is emarginate anteriorly, and is denticulate as in the previous stage. 

 A few denticles occur on the lateral margins of the carapace by the antero-lateral spines. 

 The carapace has a long and strong posterior projection. 



The antennular spine is as long as the sum of the second and third peduncular seg- 

 ments ; the flagella are unsegmented. 



The degree of development of the thoracic limbs is as follows : 



Second limb. Endopod of five segments and setose. A strong gill bud which may be 

 branched. 



Third limb. Bifurcating, non-setose, with a strong gill bud which may be branching. 



Fourth limb. A free simple bud. 



The tergal wings are developed further, the spine of the third abdominal somite is 

 stronger, than in the previous stage. The telson is the same as in the third Calyptopis 

 and the first Furcilia. 



Furcilia, stage III 



Description based on three specimens, s-y, 5-8 and ca. 6-5 mm. long. 



In this stage there are four pairs of setose and one pair of non-setose pleopods. 



In one the dorsal organ is strong but not very high ; in the other two it is low. The 



