162 Mr. G. A. Boulenger on the Suborders and 



The arrangement here proposed has been used in the 

 ' Zoological Record ' for 1902, which has just appeared. 



The precise definition of the order Teleostei, as compared 

 with the Holostean Ganoids, is a matter of some difficulty. 

 The most important character appears to be the presence of 

 an ossified supraoccipital bone. Remnants of primitive 

 characters, such as Ganoid scales, fulcra, rudiments of a 

 splenial bone, spiral valve to the intestine, multivalvular 

 bulbus arteriosus, are still found in some lower Teleosteans, 

 but no longer in that combination which characterizes the 

 preceding Order. Although Albula is exceptional among all 

 Teleosteans in having two transverse series of valves to the 

 bulbus arteriosus instead of one, no Ganoid has fewer than 

 three. The order Teleostei, thus defined, is divided into 

 thirteen suborders, the probable relations of which are 

 expressed in the following diagram: — 



— XI. Opistbomi. XIII. Plectognathi. XII. Pediculati. 



IX. Anacanthini. X. Acauthopterygii. VIII. Percesoces. 



VII. Catosteomi. V. Haplomi. VI. Heteromi. 



, — IV. Apodes. 



' — III. Symbranchii. 



I. Malacopterygii. II. Ostariophysi. 



Ganoidei Holostei. 



In the classification of Giinther, which has been generally 

 in use in this country for the last thirty-five years, the 

 Teleosts were divided into six principal groups, regarded as 

 of ordinal rank : — 1. Acauthopterygii ; 2. Acanthopterygii 

 Pharyngognalhi ; 3. Anacanthini; 4. Physostomi ; 5. Lopho- 

 branchii ; (5. Plectognathi. Group 1 corresponds to Suborders 

 VI. (part.), VII. (part.), VIII. (part.), X., XL, and XII. 

 of the present classification ; Group 2 to Suborder X. (part.) ; 

 Group 3 to Suborders IX. and X. (part.) ; Group 4 to Sub- 

 orders I., II., III., IV., V., VI. (part.), and VIII. (part.) ; 



