ESOCIFORMES 399 



SOB-TRIBE B. The mouth margined by the premaxilla only. An 

 adipose fin usually present. 



Family SCOPELIDAE. A large and important family of marine fish, 

 dating from Cretaceous times. Many of them are deep-sea forms with 

 brilliant phosphorescent organs (Fig. 344, A). The pelvic fins, with from 

 seven to ten dermal rays, may be placed far forwards. 



Ipnops has lost its eyes, and acquired two large cephalic phos- 

 phorescent organs ; Odontostomus is scaleless and has enormous eyes and 

 barbed teeth ; Bathypterois has lengthened sensitive filaments borne by 

 specialised lepidotrichia (Fig. 512, A). The air-bladder may be lost. 



Sardinoides, van der M. ; Acrognathus, Ag. ; Leptosomus, van der M., 

 Europe and Asia ; Rkindlus, Ag. ; Sardinius, van der M., Europe and 

 N. America ; Nematonotus, A. S. W., Syria ; Scopeloides, Wettstein ; 

 Dactylopoyon, van der M. ; Parascopelus, Sauv. ; Anapterus, Sauv. ; 

 Apateodus, Ag., Europe ; all from the Cretaceous. Scopelus, Cuv. ; 



FIG. 390. 

 Dallia pectoralis, Bean. (From Jordan and Evermann.) 



Ipnops, Gtlir. ; Sudis, Raf. ; Paralepis, Risso ; Bathypterois, Gthr. ; 

 Harpodon, Les. ; Odontostomus, Cocco ; Bentlwsaurus, G. and B. 



Family ALEPIDOSAURIDAE. Powerfully toothed elongated fish, with 

 an immense dorsal fin, no scales, no air-bladder, and a simple post- 

 temporal attached to the opisthotic. The single genus appears to be 

 closely allied to the Scopelidae. 



Alepidosaurus, LoAve (Fig. 391) ; Atlantic and Pacific. 



Family CETOMIMIDAE. Deep-sea fish, whose affinities are very uncer- 

 tain, with a huge mouth, small teeth, and no scales. Cetomimus has lost 

 the pelvic fins, and has very small eyes. 



Cetomimus, G. and B. (Fig. 392) ; Ronddetia, G. and B. 



SUB-TRIBE C. The maxillae are excluded from the margin of the 

 mouth, which usually has a small gape, with the suspensorium produced 

 forwards ; and the centra have well-developed parapophyses. Without 

 an adipose fin. 



Family KNERIIDAE. With toothless non- protractile jaws, small 

 scales, opercular membranes confluent, a narrow gill -opening, pelvic 

 fins with nine dermotrichs. 



Kneria, St. ; rivers of Tropical Africa. 



