558 PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 



their relatious, I have examiued their osteology, and am now convinced 

 that, notwithstanding this deviation, they are most nearly connected 

 with Chsetodonts. They exhibit the following external and skeletal 

 characteristics. 



EPHIPPIID^. 



Sj/noni/my. 



= Ei)liippioids, Gill, Proc. Acad. Nat. Scl. Phila. [v. 14,] p. 238 (uot defined), 1862. 



=: Epliippiidfe, Gill, Artaiigement Families Fishes, p. 8 (uamed only), 1872. 



= Epliippidi, Poeij, Anal, de la Soc. Esp. de Hist. Nat., t. 4, p. 7 (named only), 1875. 



Squamipennesgen., Cuvier, etc. 



Clia»!todontid8B gen., Bonaparte, etc. 



EPHIPPIIN^. 



Sj/nonymy. 



<^ Ephippiformes, Bleeler, Enum. Sp. Piscium Archipel. ludico, p. xx, 1859. 



< Cliajtodipteriformes, Bleelrr, Archives N^erlandaises, t. 11, p. 300 (s. f. of Chacto- 



dontoidei), 187(1. H 



C'bactodontinsB gen., Bonaparte, Giinther, etc. 



l)ody mneh compressed and elevated, highest under the dorsal spines, 

 and with the caudal peduncle short. 



Scales of small or moderate size, either very finely ciliated or smooth, 

 covering the whole body and head, and encroaching on nninterruptedly 

 and more or less investing the vertical fins. 



Lateral line continuous, paralhd with the back and ending at the base 

 of the caudal fin. 



Head moderate, much compressed, short and high; eyes moderate, 

 high and lateral, situated nearly midways between the snout and oc- 

 ciput. 



Infraorbital chain with the bones decreasing backwards, and none 

 articulated with the preperculum ; preorbital moderately developed. 



Opercular bones normal. 



Ilfostrils double. 



Mouth moderate, terminal, with the cleft lateral, scarcely extending 

 to the vertical of the eyes. Upper jaw not or little protractile. 



Teeth setiform, in a band in each jaw ; none on the palate. 



Branchial apertures lateral and separated from each by a wi<le, .scaly 

 isthmus. 



Branchiostegal rays seven on each side. 



Dorsal fin commencing some distance behind the nape, and thence 

 extending nearly to the caudal; its spinous and soft jjortions are un- 

 equally developed; spinous poi'tion highest about the third spine, and 

 emarginated behind ; the soft long and elevated in front. 



Anal fin similar to and opposite the soft dorsal, and armed in front 

 with three spines. 



Caudal fin expanded vertically and with its margin concave. 



