118 Mr. C. T. Regan on the 



loi)cd muciferoiis channels and cavities, and during growth 

 the muciferous system seems to extend from the head over 

 the body as a superficial network of canals, this extension 

 being accompanied by the falling off of the scales or else the 

 scales being pierced by pores. 



The lateral line is continuous, its scales with a short, 

 straight, and wide tube. 



In all the genera it appears tliat the liver is small, the 

 intestine long, the pyloric appendages in small number, but 

 usually each with numerous small ea^ca, forming an arbo- 

 rescent mass ; sometimes the pyloric appendages are large and 

 simple, and lliggio * has recorded an instance of a specimen 

 of Centrolophus niger, in which species this is usually the 

 condition, which had the pyloric appendages excessively 

 branched. This is a good example of that kind of variation 

 which Bateson considers of much importance in the origin of 

 species, and also shows that the character of the pyloric 

 appendages is of no great value in defining genera. The air- 

 bladder is either present or absent. 



Most of the fishes of this family are known chiefly from 

 young specimens, which swim freely near the surface in the 

 open ocean, feeding on pelagic Crustacea and the fry of other 

 fish. Larger specimens have been rarely taken at considerable 

 depths, and tkere seems fair ground for the conclusion that 

 the adult fishes are in many cases inhabitants of the deep sea. 



The differences iri the vertebral column are best presented 

 in tabular form, and the figures in the various columns 

 represent : — A, total number of vertebra? ; B, praecaudal 

 vertebrae; C, praicaudal vertebrae without ribs; D, preecaudal 

 vertebrae without transverse processes, with sessile ribs ; E, 

 prfficaudal vertebraj with transverse processes and sessile ribs ; 



F, prajcaudal vertebra? with ribs on transverse processes ; and 



G, praecaudal vertebra? with closed ha?mal arch. H, prai- 

 caudal vertebra? with epipleurals on neural arch ; K, on ribs ; 

 L, on transverse processes ; and M, on vertebrae. N, caudal 

 vertebrae. 



Stromateus Jiatola .... 



Nomeus Gronuvii 



Stromateoides cinereus. . 



Cubiceps gracilis 



Psenes ci/anophrt/s .... 

 Peprilus triacanthus . . 



Seriolella jiorosa 



Lirus oralis ".i'o 



Pscnopsis ano7iiahis . 



Riggio, Naturalista Sicil., Ann. liii. p. 206 (1894). 



