6i4 



TELEOSTEI 



definite one, and it has been used for the division of these Fishes 

 into genera or sub-genera.^ The ventral fins have a more forward 

 position than in most other members of the Family. 



Fam. 7. Alepidosauridae. — Characters as in the preceding, 

 but supratemporal sirajjle, attached to the opisthotic, and dorsal 

 fin very long, formed of slender, non-articulated, simple or bifid 

 rays, extending along nearly the whole length of the back, 

 followed by a small adipose fin. The air-bladder is absent and 

 the body scaleless. The skeleton is feebly ossified ; the dentition 

 is very powerful, some of the teeth on tlie palate and mandible 

 being very strongly enlarged. 4 or 5 species are known, from 

 considerable depths in the Atlantic and Pacific Oceans, referable 

 to one genus, Alepiclosaurus or Plagyoclus. A. ferox, from the 

 Atlantic, reaches a length of 4 feet. 



Fig. 372. — Alepidosaurus femx, 1 iiat. size. (After Goode and Bean.) 



Fam. 8. Cetomimidae. — The affinities of the recently dis- 

 covered genera Rondeletia and Cetomimus, deep-sea Fishes from 

 the North Atlantic, at depths of 1000 to 1600 fathoms, are still 

 uncertain, as the skeleton could not be examined ; they are 

 probably most nearly related to the Scopelidae. The head is 

 enormous, with very wide gape, that of Cetomimus being 

 suggestive of that of a Eight Whale ; the teeth are small and 

 coarsely granular ; the gill-openings are very wide ; the body is more 

 or less compressed and scaleless ; the dorsal and anal fins are 

 opposed to each other ; no adipose dorsal fin. In Rondeletia, the 

 eyes are moderately large, and ventral fins, with 5 rays, are present; 

 in Cetom.imus, the eyes are very small, and ventral fins are absent. 



' Of. Raffaele, Mitth. Zool. Stat. Neap. ix. 1889, p. 179; Liitken, " Spolia 

 Atlantica," ii. 1892 ; Goode and Bean, '-Ocean. Ichthyol." p. 70 (1895). 



