280 



THE VOYAGE OF H.M.S. CHALLENGER. 



in Pachystomias microdon, 



12. Suborbital organs with reflector, 

 a. Distribution, 

 h. Structure, 



(1) General, . 



(2) Special description of the suborbital organa 



a. General appearance, . 

 13. The smaller anterior organ, 

 y. Tlie larger posterior oi-gan, 



c. Innervation, 



(1) In general, . 



(2) The brain of Echiostoma barhatum. 



d. Functiwi, 



e. Development, 



CONCLUSION, 



a. Comparison of the different phosphorescent organs of fishes. 



b. The typical phosphorescent cells, . 



c. The phosphorescent organs of fishes compared with those of some other animals, . 

 Scheme of the development of phosphorescent organs, 



EXPLANATION OF PLATES, .... 

 Key to the figures on the Plates, . . . 



PAGE 

 319 



319 

 320 

 320 

 320 

 320 

 320 

 322 

 322 

 .322 

 322 

 323 

 323 



323 

 323 



324 

 325 

 327 



328 

 328 



