236 OF DEEP-SEA FISHES IN GENERAL 



spiny dogfishes {Centrophorus Rossi and Centroscy Ilium 

 ornatum) and rays of our depths, also by the Macru- 

 ridce and Alepocephalidcs, in all of which, when they 

 are brought to the surface, the flesh is as brittle as 

 tinder and the bones are quite soft and crumbly. The 

 feature is one which can hardly be exhibited in a 

 drawing, but the accompanying figures of Centroscyllium 

 oj^natum (Fig. 30) and Macrurtts investigato^ns (F'ig. 31) 

 may perhaps give a general idea of the weirdness of 

 these denizens of the deep : they also serve to show 

 the large eye and sombre colouring of these typical 

 deep-swimming forms. 



We have already considered the ways in which 

 the natural darkness of the depths is lightened and 

 obviated, so that only a minority of abyssal fishes 

 have lost their eyesight. Of this minority, good Indian 

 examples are Bathypterois guentheri (Fig. 41), Onirodes 

 glomerosus (Fig. 32), and the deep-sea eels Dysomma 

 and Dysommopsisy in all of which species the eyes are 

 extremely small and more or less defective. In an 

 electric Ray {Benthobatis moresbyi, Fig. 33) dredged in 

 430 fathoms off the Travancore coast, the eyes are 

 still smaller and more rudimentary ; but, curiously 

 enough, this ray, though it must be quite blind, has 

 a row of minute luminous glands along the edge of 

 its disk, these probably being lures to attract prey. 

 In Tauredophidium hextii (Fig. 34), dredged in the Bay 

 of Bengal at the great depth of 13 10 fathoms, the 



