678 DEPTHS OF THE OCEAN 



Our contribution to the knowledge of this subject consists 

 mainly in determining the vertical distribution of the silvery 



Fig. 495. 

 ria lucetia, Garm. Nat. size, 4 cm. 



luminous Sternoptychidee and Stomiatidse more exactly than had 

 previously been done (see Fig. 478, p. 629, showing the vertical 



distribution of some 

 of the most peculiar 

 luminous fishes). 

 Fig. 495 represents 

 one of these, Vinci- 

 guerria hicetia with 

 its numerous power- 

 ful light-organs, the 

 structure of which, 

 according to Brauer, 

 is shown in Fig. 

 496, where we see 

 the black pigment 

 behind the reflector, 

 the gland, and the 

 lens (see also Fig. 

 493' 7' which shows 

 a section through the 

 light-organ in Cyclo- 

 thone). 



Splendid light- 

 organs have also 

 been discovered in 

 squids, and Chun 

 has described them 

 in many species (see 

 Fig. 434, p. 590). These forms are entirely pelagic. The 

 Octopoda, being bottom animals, possess no light-organs. In 

 the large group of squids light-organs have also been found in 





Fig. 496. 

 Light-organ of Vinciguerria lucetia, Garni., from 

 of body (about ~\-). dr, glandular cells ; /, 

 fleeter; p, black pigment. (From Brauer.) 



central series 

 lens ; r, re- 



