"»j<9»e/i3«H!>Mr5=-.-r 



686 DEPTHS OF THE OCEAN 



These are the explanations offered at present, but they open 

 up new questions. How is it possible, for instance, for the 

 bathypelagic fishes to find their food in the dark, sparsely popu- 

 lated, water-layers ? Clearly we can advance no farther in this 

 field without more knowledge 

 gathered from new and ex- 

 tensive investigations. Even /- 

 with our present knowledge, ^ 

 and accepting the explanations 

 given as perfectly correct, many 

 questions arise in regard to de- ', ^ 

 tails. I will mention one very i^^^' ^' 

 interesting instance. ^ ^" 



During the "Challenger" 

 Expedition some specimens 

 were captured of a certain 

 blind fish i^Ip7iops murrayi), 

 which was taken in the trawl 

 only at great depths, between c^^r 

 3000 and 4000 metres. As y 

 already mentioned, the 

 "Michael Sars " also captured 

 a small blind fish, apparently a 

 near ally of Ipnops, which we ^^e^ 

 have called Bathymicrops regis ^ >y i 

 (see Fig. 305, p. 416). Ipnops ^ 

 and Bathymicrops both belong 

 to the family Scopelidee, and 

 among allied forms we find a 

 remarkable series in respect V 

 to the development of the eyes. 

 This series has been repre- 

 sented in Fig. 501, a to e : — 



a represents the head of 

 Chloropkthalmus prodiichis, Gthr., taken at Fiji in 575 metres. 



b represents the head of Bathypterois dubius, Vaill., taken 

 by the " Talisman " at the Canaries, and by the " Michael Sars " 

 at Station 41 between 843 and 1635 metres, 



c shows the head of Benthosaurus grallator, G. and B., 

 taken off America, and by the "Michael Sars" at Station 53 

 in about 3000 metres, 



^ shows the head of Bathymicrops regis, n.g,, n.sp., taken by 

 the " Michael Sars " in about 5000 metres. 





Fig. 501. 

 Development of Eyes in Scopelids. 



