141 



crammed with leucocytes : the microscopic appearance is very much like that of 

 the cortex of mammalian lymphatic gland. 

 Regd. Nos. 13122, 13181. 



115. Cyclothoiie microdon (Gunther). 



Gonostoma microdon, Gunther, Ann. Mag. Nat. Hist. II. 1878, p. 188, and Challenger Deep-Sea Fishes, p. 175 ■' 

 Alcock, Ann. Mag. Nat. Hist. Dec. 1889, p. 399 : Lutken, Vid. Selsk. Skr. (6) Nat. Math. Afd. VII. 1892, 6, p. 280, 

 pi. ii. figs. 4, 5. 



Cyclothone lusca, Goode and Bean, Ball. Mus. Comp. Zool. X. 1883, p. 221 : A. AgasBiz, Ball. Mus. Comp. Zool. 

 XV. 1888, p. 22, fig. 196. 



Cyclothone microdon, Goode and Bean, Oceanic Ichthyology, p. 99, fig. 114: Jordan and Evermann, Fishes N. 

 Amer. p. 582 : Collett, "Hirondelle" Poissons (Monaco, 1896) p. 130. 



B. 9. D. 12-13. A. 17-21. P. 9-10 V. 5? 



The chief differences, besides the much smaller size and much shorter anal 

 fin, that separate this species from C. elongatum, are the following : — 



The eye is minute. 



The teeth in the upper jaw are numerous, and gradually increase in size 

 from before backwards, one or two in the premaxilla and a few in the posterior 

 half of the maxilla being slightly enlarged : the teeth in the lower jaw, which are 

 also extremely numerous and close set, also gradually increase in size from before 

 backwards. 



The narrow ventrals reach beyond the vent. 



There are no glandular (luminous) masses on the edges of the caudal 

 peduncle. 



Bay of Bengal, off Andaman Is. 485 fathoms : Andaman Sea, 265 fathoms. 



Regd. Nos. 12455, 12468. 



Besides the " Investigator" specimens there are several of the " Challenger " 

 duplicates in the Indian Museum. 



Photichthys, Hutton. 



Phosichthys, Hntton, Cat. Fishes New Zealand, p 55. 



Photichthys, Gunther, Challenger Deep-Sea Fishes, p. 177 : Goode and Bean, Oceanic Ichthyology, p. 104. 



Body elongate compressed, with thin extremely deciduous scales. Series 

 of conspicuous luminous organs extending along the ventral aspect of the body 

 from the chin to the caudal fin. Head compressed, the bones thin but ossified. 

 Cleft of mouth oblique, extremely wide, the maxilla, which extends nearly to the 

 angle of the preoperculum, forming the greater part of the margin of the upper 

 jaw ; the lower jaw projecting. Both jaws with a single series of teeth. A 

 fang on either side of the head of the vomer. Teeth on the palatines and 

 sometimes on the pterygoids. Eye moderate. 



