CONTRIBUTIONS TO THE MORPHOLOGY OF 

 THE BRAIN OF BONY FISHES. 



C. L. AND C. JUDSON HeRRICK. 



I. — SILURID^E. — With Plate XVII. 



C. JuDSON Herrick. 



The family Siluridae, comprising the cat fishes and bull- 

 pouts, forms a very convenient starting point for a discussion 

 of the brain of the teleosts. It is a very close family, at 

 least as far as our inland fresh- water forms are concerned, 

 and at the same time it is distributed in great abundance 

 over the entire North American Continent with considerable 

 diversity of habitat. 



Of all the Teleostei the Siluridse, according to Prof. 

 Cope,(') are more closely related in internal structure to the 

 gars and other ganoids. The brain, however, is as distinctly 

 teleostean as that of any other fish examined and shows very 

 little evidence of any close relationship with the ganoid 

 fishes. On the other hand, the elongation of the olfactory 

 crura, the structure of the cerebrum, the extrusion of the 

 cerebellum and the form of the medulla all suggest affinities 

 with the more highly specialized teleosts, while the brain of 

 some of the other bony fishes, particularly the mud-eating 

 fishes, Hyodon, Dorosoma, etc., has a very pronounced 

 reptilian aspect. Judging from brain characters alone, the 



I Fide Jordan and Gilbert, " Manual," p. 95. 



