518 BULLETIN 10 0, UNITED STATES NATIONAL MUSEUM 



auditory ossicles. Mesocoracoid arch always well developed, forms 

 bridge from hypercoracoid to hypocoracoid. Shoulder girdle well 

 developed, joined to cranium by bony post-temporal. Scales usually 

 cycloid. No developed photophores. Dorsal and anal fins without 

 true spines. Ventrals abdominal, sometimes absent. 



A large group of marine fishes, seldom in fresh water, the fossils 

 fewer though better represented than most bony fishes. As some 

 show characters like those of the higher ganoids or bowfins, these 

 liave been thought to suggest possible lines of descent. 



ANALYSIS OF FAMILIES 



a\ Cltjpeoidei. Scales cycloid, absent from head ; mouth without barbels. 

 h\ Dorsal median, not far posterior. 

 &■. Lateral line present. 



<Z\ Branchiostegals 12 to 20 or more. 

 e\ Gular plate present between each ramus of lower jaw ; mouth large ; 

 teeth small, pointed ; axillary scales and sheaths large ; dorsal 



median or before anal Elopidae 



e^. No gular plate at chin. 



/■*. Dorsal median, over ventral; mouth inferior Albulidae 



f. Dorsal post median, over anal ; mouth superior or terminal. 



Osteog'lossidae 

 (J-. Branchiostegals 4 to 9. 



<7\ Anal short, posterior. 



ft\ Dorsal median, rays few Chanidae 



7)^. Dorsal extensive over back, rays numerous Pterothrissidae 



[/-. Anal greatly elongate, confluent with abortive caudal ; dorsal 



small or absent Notopteridae 



cl No lateral line. 



j\ Stomach gizzardlike ; mouth small, inferior, toothless ; 



maxillary simple or nearly so Dorosomidae 



r. Stomach not gizzardlike. 



/. Mouth moderate, terminal ; maxillary usually in 3 pieces. 

 k^. Belly rounded, covered with ordinary scales ; supple- 

 mental maxillary very narrow Stolephoridae 



/cl Belly compressed, with bony serrae ; supplemental maxil- 

 lary broad Clupeidae 



f. Mouth very large, partly to quite inferior, below tapering 



piglike snout ; maxillary very long Engraulidae 



6^ Dorsal far back, opposite anal ; teeth large Chirocentridae 



a'. GoNORYNcnoiDEi. Scales ctenoid, covering head as well as body ; mouth with 

 barbels Gonorynchidae 



Family ELOPIDAE 



Body elongate or oblong, mostly compressed. Mouth large, termi- 

 nal, lower jaw conspicuous, lateral borders of jaws formed by maxil- 

 laries. Premaxillaries short, not protractile. Maxillary with two 

 supplemental bones. Elongate bony gular plate between branches 

 of lower jaw. Villiform teeth in jaws, on vomer, palatines, 



