Classification of the Percoid Fishes. 13? 



operculum; skull long, flattish above, with a short occipital 

 and no parietal crests; nasals long, nearly or quite meeting 

 above the mesethmoid 3 no subocular shell'. Pectoral arch 

 lVrciform, the -1 radials normally hourglass-shaped^ only 

 the lowest on the hypocoracoitl. Vertebrae C> ( .) (40 + 2'J) in 

 Ammodytes lanceolatus ; first very short, with the centrum 

 convex: anteriorly, fitting the single concavity formed by the 

 basioccipital and exoccipitals ; latter meeting above the 

 former; ribs blade-like, anteriorly sessile, posteriorly on 

 short parapophyses ; epipleurals mostly on ribs. 



Genera: Embolichthys, Bleekeria, Ammodytes, Hyperopias, 

 Hypoptychus. 



The systematic position of this family has been the cause 

 of considerable discussion. Boulenger interpreted the Oligo- 

 cene Cobitopsis 3 with abdominal pelvic fins, as a member of 

 this family. After examination of the examples of Cobitopsis 

 acutus in the British Museum collection I have doubt that 

 this fish is a congener of the existing Scombresocid, Chrio- 

 donis atherinoides of the coasts of Florida. 



I have carefully examined a spirit-specimen of Bleekeria 

 cullolepis and compared it with Ammodytes ; the two genera 

 are very closely related, and Embolichthys, Jordan, scarcely 

 differs from Bleekeria except in the presence of jugular 

 pelvic fins. 



The nearest allies of the Ammodytidae among the Percoids 

 seem to be the Percophiidae ; but the relationship is not very 

 close, and the Ammodytidae may well form a separate division, 

 Ammodvtiformes. 



Division 9. Champsodoxtiformes. 



Fam. Champsc-dontidae. 



Champsodon differs from the Trachiuiformes in that the 

 small pectoral fin has the base oblique; the radials are 

 elongate hourglass-shaped, 3 on the hypcrcoracoid, which 

 is quite narrow and is pierced by a small foramen, and 1 on 

 the hypocoracoid. Spinous dorsal short, separate ; soft dorsal 

 and anal long; pelvics large, close together, well in advance 

 of the pectorals. Mouth oblique \ maxillary exposed; cardi- 

 I'onn teeth in jaws and in two separate patches on vomer. 

 Gill-membranes separate, free. No mesopterygoid. limns 

 of skull arranged as in normal Perciformes, Skull de- 

 pressed, tiat above, expanded behind the orbits. Vertebrae 

 '61 (12 + 1 ( J) : praecaudals with parapophyses from the 



