288 



DE. G. H. FOWLEE — BISCATAN PLANKTON : 



It is noticeable that the specimens of Stage I. were from nets lowered to at least 350 

 fathoms : 34/, 750-500 ; 23 a (the doubtful female), 1000-750 ; and 36 I, 350-0 fathoms. 

 As the numerous captures which have hitherto been made from the Atlantic Avere 

 always of Stage II., it seems likely that the oldest stage is only to be found in deep 

 water. 



CoNCHCECiA IMBRICATA (Brady pars), MuUer. 



7 per cent, of 13 hauls, with 007 "^ 



out of 



10 

 17 



7 

 3 

 3 

 3 

 3 

 4 



average 

 2*20 L specimens 

 152 J per hour haul. 



0-00"! 



0-00 



1-00 



1-66 



100 



0-40 J 



average 



specimens per 



100 fathom 



haul. 



This species was plentiful at no depth ; it failed at and 25 fathoms. The single 

 specimen captured at 50 fathoms was only 1 mm. long, but there did not seem to be any 

 general indication that any stage had a preference for any particular level. 



It appears obvious from the table that imbricata was not present at all in the upper 

 cpiplankton, but that it extended at least to 500 fathoms. In such a case as this, where 

 the species is uncommon in the cpiplankton, it is fairly certain that the mesoplanktonic 

 specimens were living at the lower levels and were not merely falling corpses. 



It is further of interest to note that all the ten occasions on which it was captured in 

 the cpiplankton were between 7.0 p.m. and 4.0 a.m. ; this strongly suggests a rise from 

 deeper water at night ; these 10 hauls form 32 per cent, of the comparable night hauls, 

 and are therefore a fair test of the point. 



The horizontal distribution in the cpiplankton was quite local, even in the small 

 area studied : the stations were all in the southern part of the area. 



Although this species failed in the hauls with closing-nets between 250 and 100 

 fathoms, it was captured in the serial hauls 36 g, h, k (200-0, 250-0, 300-0 fathoms) 

 in such numbers as to ensure that the specimens were not merely caught in the hauling 

 of the nets to the surface. 



CoNCHCECIA INERMIS, ClaUS. 



This species was observed only in a serial haul, 36 1 (350-0 fathoms), 

 conclusion as to its horizon can be made. 



and 



no 



CoNCHCECIA KAMPTA, Miillcr. 



This was represented only by two males of the same stage, which were taken in two 

 hauls {22 b, 34 e) between 750-500 fathoms. The species was presumably purely 

 mesoplanktonic. 



