500 WILLIAM K. GREGORY 



the Haplomi, Mr. Tate Regan, who has carefully studied the oste- 

 ology of the group, concludes that the absence of non-articulated 

 fin rays, the large number of rays in the vent rals, and the lack 

 of direct attachment of the pelvic bones to the clavicles, taken 

 together, must be regarded as primitive features. "From their 

 anatomy and appearance," he says, "I am inclined to think 

 that the Gadoids are not related to the Percesoces, but are 

 derived from some Haplomous stock from which the Berycidae 

 have also descended, and of which the Stephanoberycidas may 

 well be the living representatives." 1 



The group is typically carnivorous, marine, often abyssal. 

 Fossil Gadoids are rare, but are recorded from the Eocene and 

 Miocene. 



Superorder Acanthopteroidei (cont'd). 

 Order Selenichthyes 2 Boulenger 

 (Plate XXIX.) 

 The Opahs. 



The systematic position of the Opah or Kingfish (Family 

 Lamprididae) is somewhat uncertain, but it seems entitled to 

 occupy at least provisionally a separate order. It may be re- 

 lated either (i) to the Thoracostraci as held by Boulenger, 3 or 

 (2) to such deep-bodied Scombroids as Brama and Mene (Gill). 4 

 or it may possibly be ' ' transitional between deep-bodied extinct 

 Ganoids [such as Dorypterus] and the forms allied to Platax, 

 Zeus, and Antigonia" (Jordan). The Opahs resemble the 

 Bramidse in the heaviness of the shoulder girdle and in the great 

 dilatation of the coracoid (hypocoracoid) ; superficially they 



1 ' ' On the Systematic Position and Classification of the Gadoid or Ana- 

 canthine Fishes." Ann. and Mag. Nat. Hist. (7), Vol. XI, May, 1903, pp. 

 459-466.^ 



2 GsXt/vt/, the moon, i'x^ v ^y fish, in allusion to the gibbous form of the 

 body. 



^Boulenger, G. A., " Notes on the Classification of Teleostean Fishes. 

 III. On the Systematic! Position of the Genus Lampris, and on the 

 Limits^and Contents of the Suborder Catosteomi." Ann. and Mag. Nat. 

 Hist., Vol. 10 (Ser.), Aug., 1902, pp. 147-152. 



4 Gill, T. "On the Relations of the Fishes of the Family Lamprididse or 

 Opahs." Proc. U. S. Nat. Mus., Vol. XXVI, 1903, pp. 915-924. 



