ACTINOPTERI. 177 



The recent forms comprise about two genera, and are oceanic or 

 pelagic, resemble the sword fishes, though of smaller size. The 

 fossils, known only from fragmentary rostra, have been referred 

 to the existing 1st lop homs and two other genera. 



Genus ISTIOPHORUS Lacepede. 



Istiophorus Lacepede, Hist. Nat. Poiss. Ill, 1802, pp. 374, 375. Type 



Istiophorus gladifer Lacepede, monotypic. 

 Histiophorus, auct. 

 Makaira Lacepede, 1. c, IV, 1803, pp. 688, 689. Type Makaira nigricans 



Lacepede, monotypic. 

 Madiera, Macaria, auct. 

 Nothistium Hermann, Observ. Zool., 1894, p. 304. Type Histiophorus ameri- 



canus Valenciennes, virtually, as based on Guebucu Marcgrave, though 



no binomial given. 

 Zanclurus Swainson, Nat. Hist. An., II, 1839, p. 239. Type Zanclurus in- 



dicus Swainson, monotypic. 



Body slender, much compressed. Rostrum usually shorter and 

 less flattened than in sword fishes, edge more rounded, and man- 

 dible more developed. .Many small teeth on jaws and palatines. 

 Air-vessel sacculate. Intestine short, nearly straight. Body cov- 

 ered with elongate scales, rougher than sword fishes. Dorsal fin 

 very high, continuous, as in young spear fishes and sword fishes, 

 rays numerous, none aborted, first rays much higher than body 

 depth. Anal divided. Ventral present, rays 2 or 3. 



The recent forms large fishes of warm seas, the number of 

 species uncertain, likely several, and one recently found on our 

 coast. About six extinct forms. 



Istiophorus antiquus (Leidy). 



Xiphias antiquus Leidy, Proc. Acad. Nat. Sci. Phila., VII., 1855, p. 397. 

 Greensand of Burlington Co., N. J. (C H. Budd.) 



Histiophorus antiquus Cope, Proc. Boston Soc. N. H., XII, 1869, p. 310 (ref- 

 erence). 



Rostrum well depressed, transversely oval in section, its short 

 diameter about one-half its long diameter, and anteriorly becom- 

 ing more cylindrical. Length about 265 mm. (From Leidy.) 

 12 GEOL 



