36 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 124 



Internal organs. — The peritoneum is black. The stomach is 

 straight, elongate, and thick walled. There are six finger-like pyloric 

 caeca. The gas bladder extends nearly the full length of the abdominal 

 cavity and is rounded at both ends. 



Discussion 



Roule (1922, 1929) and Grey (1960) agreed that Scombrolabrax is 

 related to the gempylid fishes. Both authors have noted the similarity 

 in general appearance between Scombrolabrax and the gempylid genus 

 Epinnula. Grey demonstrated in some detail the similarities between 

 the peculiar lateral-line scales of gempylids and those of Scombrolabrax. 

 The upper jaw structure with its long supramaxillary and its fang 

 duplicates that of the Gempylidae as illustrated by Matsubara and 

 Iwai (1958, fig. 3). The skull roof, as previously noted, seems to be 

 that of the gempylid Ruvettus. The spinulose gill rakers again are like 

 those of gempylids. Indeed, there seems nothing about Scombrolabrax 

 that would militate against a Scombrolabrax-gempylid relationship. 



In most instances wherein Scombrolabrax differs from the gemylids, 

 it differs in the direction of the percoids. Thus, in Scombrolabrax, the 

 upper jaw is protrusile, some of the opercular bones are spinous or 

 serrate, the pelvic girdle is relatively strong and firmly attached to 

 the cleithra, the parts of the caudal skeleton are not fused, the lateral 

 line is simple, the lateral-line scales bear a groove rather than a com- 

 pletely bone-enclosed tunnel (Grey, 1960), the number of vertebrae 

 is relatively low, etc. 



If Scombrolabrax is included in the trichiuroid fishes and if the 

 trichiuroids and Scombridae are combined in a single suborder, the 

 difficulties of defining the suborder become considerably greater. The 

 best that I can do in this regard is as follows. 



The suborder Scombroidei are perciform fishes with nonprotrusile 

 upper jaws (except Scombrolabrax), the postorbital members of the 

 circumorbital ring of bones represented either by numerous small 

 pieces or absent, the interorbital commissure of the supraorbital 

 canals widely incomplete or lacking, the predorsal bones (Smith and 

 Bailey, 1961) lacking, and the vertebrae numbering 30 or more. 



Regarding the origins of the Scombroidei and more especially the 

 Scombridae, these frequently have been postulated to lie in the area 

 of the percoid family Carangidae (e.g., Starks, 1911). My own work 

 has led to the conviction that Regan (1909a) was correct in separating 

 the Scombridae widely from the Carangidae and that the rather 

 numerous morphological features held in common by members of the 

 two families (Starks, 1911) are the result of convergence. The reasons 

 for this conclusion are as follows : 



(1) In the Carangidae (see Suzuki, 1962), the supraoccipital crest 

 always is carried forward on the frontals to the ethmoid region and 



