ON THE RELATIONS OF THE FISHES OF THE FAMILY 

 LAMPRIDID.E OR OPAHS. 



By Theodore Gill, 



Associale in ZnoJogj/. 



Dr. Boulenger, in the third number of his sug-o-cstivc and v}Uua})lc 

 Notes on the Class itication of Teleostean Fishes, has published some 

 novel ideas respecting- the systematic position of the Opah. He has 

 found the same number of bones in the scapular arch as in that of 

 normal Acanthopterygians, but has homologized them ditferently from 

 his predecessors. The "very large bone to which the pelvis is 

 attached" is designated as an '' infraclavicle" andhomologized with a 

 so-called infraclavicle of Hemibranchiate fishes. A comparative!}^ 

 small liono in serial relation with the actinosts or "pterygials" is 

 identified as the homologue of the hypocoracoid or "coracoid"' of ordi- 

 nary Acanthopterygians. There would then be only three actinosts or 

 "pterygials," and it is especially remarked that the foremost of these 

 is "fused with " the hypercoracoid or " scapula." As a result of these 

 identifications. Dr. Boulenger thinks that "all difficulties from the 

 systematic point of view disappear at once" and that "the Opah must 

 be regarded as more nearh' allied to the Hemibi'anchii than to an}' 

 other group of fishes with which we are as 3'et ac(j[uainted.'' Conse- 

 quently the Opah is isolated not onl}' as the representative of a dis- 

 tinct family {Lamjrrididw)^ but an independent group {Sf/enic/it/ii/c-t) 

 of a new suborder {Oaiosteomi), which includes also the iremihranchii 



and Lophohrcmchii. 



IL 



The great respect and admiration I have for Dr. Boulenger's work 

 has led me to consider ver}^ carefully the grounds for the determina- 

 tions in question, but I find greater difficulty in accommodating myself 

 to his views than in accepting those (or nearly those) of his prede- 

 cessors. Among the latter was William Kitchen Parker, Avho in 1868 

 commented on the structure of the Opah in A Monograph of the 

 Structure and Development of the Shoulder Girdle (p. 51). His 

 identifications essentially correspond with those now to be given, 

 although his meaning is somewhat obscured by the curious mode of 

 expression to which he was addicted. At any rate, he writes that 



Proceedings U. S. National Museum, Vol. XXVI-No. 1340. 

 Proc. N. M. vol. xxvi— 02 61 t»i'5 



