60. CENTRISCIDJE. 387 



terior margin of orbit; tail longer than bead and body together; snout 

 rather shorter than opercle ; supraorbital spine nearly half diameter of 

 eye; coronet well developed, with five spines. D. 19; A. 4. Rings 10 

 -4- 38. San Diego, Cal., and southward ; reaching a length of nearly a 

 foot. 



(Girard, U. S. Pac. R. R. Surv. Fishes, Irt58, 342.) 



ORDER S. HEMIBRANCHII. 



(The Hcmibranolis.} 



Superior branchihyal and pharyngeal bones reduced in number; in- 

 ferior pharyngeals separated. Ventral fins abdominal or subabdominal. 

 Mouth bounded above by premaxillaries only ; interclavicles developed. 

 No pneumatic duct to the air-bladder. (Cope.} There are also several 

 striking peculiarities in the structure of the shoulder girdle and the skull, 

 by which these fishes differ from the Acanthopteri, with which group un- 

 der one name or another they have usually been combined, (^//.j, half; 



ANALYSIS OF FAMILIES OF HEMIBRAXCHII. 



* Bones of head produced into a long tube, which bears the short jaws at its end. 

 a. Body short, compressed, scaly ; no teeth ; spinons dorsal present. 



CENTRISCID^E, GO. 

 aa. Body elongate ; teeth present. 

 l>. Dorsal spines none ; a long caudal filament ; no scales ..... FISTULARIID.E, 61. 



6&. Dorsal spines present, disconnected ; no caudal filament. 

 c. Body covered with ctenoid scales ............ , ....... AULOSTOMATID.E, 62. 



cc. Body scaleless, with bony shields ................... AULOKHYNCIIID/E, Q>.}. 



** Bones of head moderately produced ; veutralsl, 1 ; dorsal preceded by free spines; 

 body scaleless, naked or mailed ........................ GASTEROSTEID^E, 64. 



FAMILY LX. CENTRISCID^. 



(The Snipe-fislics.} 



Body compressed, oblong or elevated, covered with small rough scales; 

 no lateral line ; some bony strips on the side of the back and on the 

 margin of the thorax and abdomen, the former someti ines confluent into 

 a shield. Bones of the skull much prolonged anteriorly, forming a long 

 tube which bears the short jaws at the end ; no teeth. Gill-openings 

 wide ; branchiostegals 4. Two dorsal fins, the first of 4 to 7 spines, the 

 second of which is very long and strong ; soft dorsal and anal moderate ; 

 ventral fins small, abdominal, of 5 soft rays ; pectorals short ; caudal fin 

 emarginate, its middle rays not produced. Air-bladder large ; pseudo- 



