Jordan and Evermann. Fishes of North America. 741 



1095. EXOCCETUS GIBBIFRONS, Cuvier & Valenciennes. 



Head 43 ; depth 6. D. 12 ; A. 8. Body robust, little compressed. Head 

 rather short, interorbital area slightly concave, about i wider than eye ; 

 profile of snout convex, descending more abruptly than in any other of 

 our species, making a decided curve downward. Snout rather blunt, 4 in 

 head ; eye 3 in head ; maxillary 4| in head ; pectoral fins rather broad 

 and long, their length 1 in length of body; tips of pectorals reaching to 

 tips of last rays of dorsal. First ray of pectoral simple, its length 2.1- in 

 length of fin ; second ray simple, about | longer than first ray ; third ray 

 divided; fourth ray longest. Origin of ventrals midway between pos- 

 terior margin of eye and last caudal vertebra ; length of ventrals 2.9 in 

 length of body, their tips reaching to last ray of anal. Origin of dorsal 

 fin far in advance of the anal. Base of anal If in base of dorsal. Longest 

 dorsal ray 21- in head, longest anal ray about 3 in head. Lower lobe of 

 caudal about 3 in body ; least depth of caudal peduncle 3^ in head. 

 About 25 scales in lateral line before ventrals, and about 30 scales before 

 dorsal ; 7 scales between lateral line and dorsal fin. Color brown above, 

 silvery below ; on each scale on the upper part of the body is a darker 

 brown spot near its posterior extremity ; this gives the appearance of a 

 dark-brown streak alonqr each row of scales ; pectorals uniformly colored, 

 same color as upper part of body ; ventrals dusky, nearly black mesially, 

 the posterior part of the fin still darker ; no dark markings on dorsal or anal 

 fins; caudal dusky, plain. Length 8 inches. Atlantic Ocean ; two speci- 

 mens known, both examined by us ; the specimen above described taken 

 by Samuel Powell at Newport, Rhode Island, the other the original type 

 in the Museum at Paris, (gibbus, gibbous ; frons, forehead.) 



Exocaetus gibbifrons, CUVIER & VALENCIENNES, Hist. Nat. Poiss., xijc, 118, 1846, Atlantic; JOR- 

 DAN & MEEK, I. c., 65; JORDAN, Proc. U. S. Nat. Mus., 1886, 528. 



Order Z. HEMIBRANCHIL 

 (THE HEMIBRANCHS.) 



Interclavicles developed. Gills pectinate. Post-temporal simple, not 

 furcate; supraclavicle quite small. Superior pharyngeal bones reduced 

 in number, the bones of the gill arches also reduced except in Gasterosteidce ; 

 inferior pharyngeals present, not united. Ventral fins abdominal or 

 subabdominal, joined to the interclavicle, or else detached from it 

 through partial atrophy of the shoulder girdle. Mouth bounded above by 

 premaxillaries only ; shoulder girdle simple in structure. Basis of cra- 

 nium simple and without tube ; four anterior vertebras more or less 

 elongate; snout usually more or less produced, the small mouth at its 

 end. A small group, well distinguished from the Percesoces and other 

 Telcocephali, from ancestors of which it is probably descended, differing 

 in the presence of the interclavicles and in the reduction of the shoulder 

 girdle and other structures. Its relations to the Lophobranchii are close, 

 the characters of the Lophobranchii being largely extremes of the same 

 modifications, (fat, half; /tfpuy^of, gill.) 



