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



The arrangement here proposed has been used in the 

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



The precise definition of tlie 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 whicli are 

 expressed in tlie following diagram : — 



-XI. Opisthomi. XIII. Plectogualhi. XII. Pediculati. 



IX. Anacanlhini. X. Acantbopterj'gii. VIII. Percesoces. 



VII. Catosteomi. V. Ilaplomi. VI. Heteroini. 



I — IV. Apodes. 



' — III. Symbranchii. 



I. Malacopterygii. II. Ostariophysi. 



Ganoidei Holostei. 



In the classification of Glinther, 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. Acanthopterygii ; 2. Acanthopterygii 

 Pharyngognathi ; 3. Anacanthini; 4. Piiysostomi ; 5. Lopho- 

 branchii ; G. Plectognathi. Group 1 corresponds to Suborders 

 YI. (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 VJII. (part.) ; 



