124 DE. G. H. FOWLER— BISCATAN PLANKTOX : 



grouped as " niglit " ; the numbers at the various depths are average specimens per hoar 

 haul, the absence of observations being indicated by a plus sign :— 



Fathoms. 2". 3"-G". 7"-10". ll"toD. Night. 



11-7 



25 + 8-0 



50 + 2-0 13-5=K 



75 + 7-2 15-2 



100 06 4-4 8-6 



It is noticeable that a bright moon did not seem to drive the species from the surface 

 (compare captures at 21 /, 22 g) ; the average capture per hour in bright moonlight 

 was 13-3. 



The foregoing tables show pretty clearly the oscillation of this species by statistical 

 methods. The question may pertinently be put, — where was the species to be found 

 by day P The answer to this unfortunately cannot be deduced with certainty from my 

 collections. 



Three hauls out of thirteen at 100 fathoms between 4.0 a.m. and 7.0 p.m. produced 

 five specimens, Avhich work out to an average of 0-3 specimens per hour haul : still, 

 what may have been the upper fringe of the species was at or about 100 fathoms during 

 the day, so far as my hauls go. ^ 



The seven serial two-hour hauls (3G e,f, g, h, i, k, I) only caught 21 specimens among 

 them (absolute untreated numbers), giving an average of 1*5 specimens per hour haul, 

 which is surj)risingly low. 



But it is noticeable that at 250 fathoms one serial tow-net (36 i) caught as many as 12 

 specimens (6 per hour), and that the closing-nets 35 m and 35 j) caught respectively 5 

 and 10 specimens per 100 fathom haul ; in other words, these closing-nets produced one 

 specimen for every cube of (approximately) 5J feet and 7 feet which they respectively 

 filtered. This indicates the presence of a fairly large population between 250 and 100 

 fathoms in daylight. 



Meganyctiphanes korvegica. 



This species was taken solely at or between 25 and 100 fathoms. 



At 





\ 

 5 



1-8 



4-1 



2-2 / 



O -5 

 <-. p 



c "> 



c ^ 



re 



P" o 



I B 



^- re 



It occurred in only 20 per cent, of the total hauls at or between 25 and 100 fathoms. 

 Owing to its comiiaratiA'c scarcity, conclusions drawn from its distribution during the 

 ci'uise would be unconvincing:. 



* If haul 31 h were iiichided, this figure would be 60'0. 



