732 Bulletin 4j, United States National Aiuseutn. 



H: Dorsal and anal fins marked with black; dorsal with one orniore dark 

 blotches; anal with a hlack spot on tips of third to sixth rays; ven- 

 tnils black, witli pale edgings, and a white spot near the base. 



FURCATUS, 1087. 

 XJ. Ventral fin inserted midway between posterior margin of preoporcle and last 

 caudal vertebra. 

 m. Pectorals each with the posterior half rather abruptly black; anal white. 



NIOKICANS, 1088. 

 vim. Pectorals unicolor or nearly so, not abruptly black posteriorly. 



11. Pectorals uniformly black everywhere, the outer surface with silvery 



luster. XENOI'TERUS, 1089. 



nn. Pectorals nearly uniformly pale, or slightly dusky with jiale edging 

 and a palo cross shade. 

 o. Dorsal fin slightly dusky, but without distinct markings; other fins 

 faintly shaded, but without distinct black markings; pectoral 

 reaching base of last anal ray; ventrals almost as far. D. 13; 

 A. 10. LINEATUS, 1090. 



00. Dorsal fin with a round, black blotch as largo as eye on tips of 

 middle rays; other fins all pale; pectoral reaching beyond 

 tips of dorsal and anal. D. 12; A. 11. cyanoptkrus, 1091. 

 jy- Ventral fins inserted at a point midway between middle of opercle and last 

 caudal vertebra (or between tip of snout and tip of upper lobe of caudal). 

 p. Dorsal fin with a large blackish blotch; pectorals nearly uniformly dusky; 

 ventrals bluish white. Tip of pectorals reaching end of dorsal; tip of 

 ventrals reaching middle of anal; insertion of ventral midway between 

 tip of snout and that of ujiper lobe of caudal; dorsal fin of medium 

 height, inserted much in advance of anal. Snout f length of eye, 

 which is 3}{^ in head. Head 53^3 in total length (with caudal); depth 

 6%. D. 13; A. 9 or 10; scales 50. rahiexsis, 1002. 



;i;i. Dorsal fin pale, somewhat dusky above, without distinct black blotch; 

 ventrals mesially blackish, the margins paler; dorsal rather pale, 

 somewhat dusky above; pectorals mostly dusky, with the posterior 

 edges paler; an obscure oblique band across lower part. Pec- 

 torals If in length of body, their tips reaching caudal fin. Ventrals 

 3% in body, their tips reaching middle of anal. Lower lobe of cau- 

 dal about 3^ longer than head. Head 4| to 5 in length of body; 

 depth 6. D. 12; A. 10. Snout 4 in head. Eye 314 in head. Base of 

 anal 1| in base of caudal. Scales about 60. californicis, 1093. 



a. Pectoral fins covered with small, round, dark spots, the edges paler. 



callopteru.s, 1094. 

 hh. Second ray of pectoral simple (like the first); 'third ray divided. 



q. Snout more obtusely descending than in any other species, its length 4)^ in head. 



GIBBIFRONS, 1095. 



Subgenus EXOCCETUS. 



1080. EXOCCETUS EXSILIENS, P. L. S. Miiller. 



Head 4 in length of body; depth r>i. D. 11; A 11; scales 48. 

 Body little compressed, angulated. Head broad; iiiterorbital space 

 slightly concave; snout rather blunt, short, 4f in length of head; inter- 

 orbital area 2i in head; eye 2J in head; lower jaw slightly longer than 

 upper. Pectorals long and broad, 1^ in length of body, their tips reaching 

 base of caudal; iirst 2 rays of pectoral simple and of equal length, their 

 length 2i in length of fm, and connected to each other and to third ray 

 by rather broad membranes; ventrals long, 2^^ iu body, their tips reach- 

 ing base of caudal fin ; origin of ventrals midway between posterior 



