THE FISH OF THE DEEP SEA 159 



extraordinary types. The genus Bathypterois, for 

 example, occurring in depths ranging from 500 to 

 2,500 fathoms, is characterised by the development of 

 enormously long pectoral fins to serve probably as 

 organs of touch. * The rays of the pectoral fin,' says 

 Dr. Giinther, ' are much elongated. The ventral fins 

 abdominal, with the outer rays prolonged, eight- 

 rayed. . . . Gill rakers long.' They are further 

 characterised by the absence of any true phosphor- 

 escent organs and the smallness of their eyes. 



There can be little doubt, I think, that in these 

 fishes the sense of touch or taste to a great extent 

 takes the place of the sense of sight in other Sco- 

 pelids. Not being provided with well-developed eyes 

 or phosphorescent organs to attract their prey, the 

 pectoral fins and the outer rays of the pelvic fins 

 have become elongated and provided with special 

 sense organs for searching for their food in the fine 

 mud of the floor of the ocean. 



These long pectoral rays must have a very curious 

 appearance in the living fish. Mr. Murray observes : 

 * When taken from the trawl they were always dead, 

 and the long pectoral rays were erected like an arch 

 over the head, requiring considerable pressure to 

 make them lie along the side of the body ; when 



