ACANTHOPTERYGII (SPINY-FINNED TELEOSTS) 



A PECULIAR arrangement of the branchiostegal rays, characteristic of the spiny-rayed 

 fishes, is thus described by Hubbs (1919, pp. 68-70): "A definite fixed type of branchio- 

 stegal structure has been retained, almost without deviation, throughout the great groups 

 of spiny-rayed fishes which flourish so abundantly in the modern seas, and with peculiar 

 constancy in the numerous highly specialized offshoots of the typical Acanthopteri. In 

 fact, it seems safe to assert that none other of the known characters which separate this 

 series from the lower teleosts has been more conservatively maintained throughout the en- 

 tire group. ... 1- u 1 



"The characteristically stout hyoid arch is strongly angulated at some distance below 

 and before the (typically) dentate suture between the ceratohyal and the epihyal, the angle 

 forming the hinder border of a concavity in which the musculus geniohyoideus is attached. 

 The strong development of this muscle not only modifies the form of the hyoid arch, but 

 also modifies the structure and attachment of the branchiostegal rays, as it also does, usually 

 to a lesser degree and without constancy, in the lower teleosts. The upper four saber- 

 shaped branchiostegals are always attached to the outer surface of both epihyal and cerato- 

 hyal, at and above the angle of the arch, and are folded together like a fan above and behind 

 the opercular margins (except in those cases in which the branchiostegal membranes are 

 drawn taut by their broad union ventrally). Below (and before) the angle of the arch, 

 to its edge or inner surface, usually two or three shorter and slenderer rays are attached; 

 these may be reduced to one, or, very rarely, to none, and are increased, in certain berycoids 

 and blennioids to four, but never to a higher number. Thus, the branchiostegals of the 

 Acanthopteri and related groups are usually four plus two or four plus three in number, 

 rarely four plus one or four plus four, and very rarely four plus nought or even three plus 



nought." 



Since this general arrangement is characteristic of the most diversified Acanthopterygii 

 and since clear traces of it persist, even in very highly specialized groups, it may be taken 

 in conjunction with the general perch-like construction of the skull and with other well 

 known characters of the fins as one of the chief characters of the Order Acanthopterygii, 

 even though it does not seem necessary that every fish of this group should still possess all 

 the "ordinal" characters. 



As to the division of the spiny-finned fishes into suborders and superfamilies, Tate 

 Regan (1913a, p. Ill) admits that "it is largely a matter of opinion whether some of these 

 [his "suborders" of the Percomorphi] may not be regarded as ordinally distinct, or whether 

 others should not rank merely as divisions of the Percoidea." During the course of my 

 studies on the skull of many representative acanthopts I have constantly kept before me 

 his definitions of the families, divisions and suborders of the Percomorphi and related 

 "orders." In the following pages I am not proposing a formally defined classification of 

 the divisions and subdivisions of the spiny-finned series, I am merely using such words as 

 Percoidei, Mugiloidei, etc., as convenient names for more or less well known groups of fami- 

 lies, each'of which clusters around some typical form. In fact I Incline to agree with the 



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