CHIEOCENTEIDiE. 663 



Twenty-Thied Family — BATHYTHEissiDiE. 



Body oUong, with rounded abdomen, covered with cycloid 

 scales; head naked ; iarhels none. Margin of the upper jaw 

 formed hy the intermaxillaries mesially, and by the maxillaries 

 laterally. Opercular apparatus complete. Adipose fin none ; 

 dorsal fin much elongate, many rayed ; anal fin short. 

 Stomach with a blind sac ; pyloric appendages numerous. Gill- 

 apparatus well developed ; pseuddbranchim ; gill-openings wide ; 

 an air-bladder. Ova very small ; ovaries without duct. 



One genus and species only {Bathythrissa dorsalis) from 

 deep water (350 fathoms) off the coast of Japan. This re- 

 markable fish has the appearance of a Coregonus, and attains 

 to a length of two feet. Nothing is known of its osteology, 

 but possibly a fossil genus from the Gyps of Montmartre ; 

 Notceus, which has also a long dorsal fin, may prove to belong 

 to the same family. 



Twenty-Fourth Family — Chikocenteid^. 



Body covered with thin, deciduous scales; barbels none. 

 Margin of the upper jaw formed by the intermaxillaries mesi- 

 ally, and by the maxillaries laterally, both bones being firmly 

 united, in juxtaposition. Opercular apparatus complete. Adi- 

 pose fin none ; the dorsal fin belongs to the caudal portion of 

 the vertebral column. Stomach with a blind sac ; intestine 

 short, the mucous membrane forming a spiral fold ; pyloric 

 appendages none. Pseudobranchice none; air-bladder incom- 

 pletely divided into cells ; gill-opening wide. 



One genus and species only (Chirocentrus dorab) is known, 

 which is common in the Indian Ocean, and attains to a 

 length of about three feet ; it is not e'steemed as food. 

 Eemains of fishes similar to Chirocentrus are found in the 

 marl slates of Padang, in Sumatra. 



