76 



DE, G. H. FOWLER— BISCATAN PLANKTOX ; 



once by the closing tow-net, but large specimens were also captured by the closing trawl 

 between 2000-1000 and 1500-750 fathoms. The species, then, in this area is meso- 

 planktonic, and certainly ranges as deej) as to the zone 2000-1500, probably to deeper 

 water still. 



The captures, however, enable another point to be made, namely : — that older (larger) 

 specimens do not frequent even the upper zones of the mesoplankton, but the deeper 

 strata only. Specimens more than 17 mm. in length — and this is small for hamata — 

 were met with only below 500 fathoms. 



We may fairly conclude from this table that in the area studied the older specimens 

 are to be found in the deeper strata of the mesoplankton only, though the young forms 

 may frequent higher levels. Only small specimens occurred above 500 fathoms, large 

 specimens only below 500, but small specimens also occasionally occur below 500. 



This touches a question of great interest, at which, so far as I know, no connected 

 work has been done. The young of epibenthic and epiplanktonic forms mostly sjiend an 

 early or larval life at the surface : where do deep-water oviparous forms, whether 

 plankton or benthos, spend their early life ? Do they similarly seek higher levels ? and, 



