76 DISCOVERY REPORTS 



SECOND FURCILIA 



Included in this group are the following larvae in advance of the Furcilia stage just 



described : 



(a) With 3 pairs of pleopods : 2 setose, i non-setose. 



The above combinations of setose and non-setose pleopods actually occur in the 

 samples examined. It is possible, however, that other variations may be found, for in- 

 stance, five pleopods of which one pair is setose and four pairs non-setose. 



In Table XXX the frequency of occurrence of these larvae with respect to the number 

 of stations and the number of individuals is given. The average lengths are stated in the 

 same manner as in the previous Furcilia stage. For the 2nd Furcilia the average length 

 is 6-1 1 mm. and the range between 3-96 and 7-92 mm. 



The description of this stage is based chiefly on detailed examination of larvae of the 

 forms (/), (g), (h) and (j) in the list given above. The larva having the (/) form of pleo- 

 pod development was of small size with the fifth pair of legs not nearly so advanced as 

 in the larva having five pairs of non-setose pleopods described in the previous Furcilia 

 stage. In the (/) larva the pleopods of the fifth pair were small hardly distinguishable 

 buds, yet the first two pairs were definitely setose. The degree of development of the 

 thoracic limbs indicated that the larva was certainly E. siiperba. 



In this stage the rostrum is still evenly rounded without any median spine and does 

 not reach nearly to the distal margin of the basal peduncular segment of the antennule 

 (Fig. 17 b, c, d, e). There is a small lateral denticle on the postero-lateral corner of the 

 carapace (Fig. 17 a). The telson is seven-spined terminally and has the postero-lateral 

 spines unaltered (Fig. 18 a); that is to say, the innermost postero-lateral has not the 



a, lateral aspect of larva with all pleopods setose (x 12); 

 h, dorsal aspect of larva with all pleopods setose ( x 14); 



c, antennule and rostrum of larva with 3 setose, 2 non-setose pleopods ( x 35); 



d, antennule and rostrum of larva with 4 setose, i non-setose pleopods ( x 35); 



e, antennule and rostrum of larva with 5 setose pleopods ( x 35); 



/, uropod and telson of larva with 3 setose, 2 non-setose pleopods ( x 35); 



g, uropod and telson of larva with 4 setose, i non-setose pleopods (X35); 



h, uropod and telson of larva with 5 setose pleopods ( x 35); 



j, antenna of larva with 5 setose pleopods ( x 35); 



k, mandibular palps of larva with 5 setose pleopods ( x 83) ; 



/, first maxilla of larva with 5 setose pleopods, plumose condition of exognath bristles and spinules on 



terminal bristles of palp not indicated (x 165); 

 m, second maxilla of larva with 5 setose pleopods ( x 35). 



