7:2 XIPIIIIDyE XIPHIAS. 419 



the longer. Lateral line wavy and irregular, descending posteriorly. 

 Head 4^ in length; depth 5§. D. VIII-I, 2G; A. IT, 25. L. 5 feet. 

 In all warm seas, occasional on our Atlantic coast in summer. 



{Casferonti'm caiiadtis Liuii. Syst. Nat. : Elacate atlanticus Cuv. & Val. viii,334: Elacate 

 nigra Giinther, ii, 375 ; Holbrook, Ichth. S. Car. 97.) 



Family LXXIL— XIPHIID^. 



( The Sword-fishes.) 



Scombroid fishes of great size, with the body elongated, naked or 

 covered with rough rudimentary scales, and the upper jaw very much 

 prolonged, forming a "sword," which is composed of the consolidated 

 vomer, ethmoid and premaxillaries. Teeth small and rudimentary, or 

 wanting. Dorsal tin long, usually divided in the adult, continuous in 

 the young, without diflerentiated spinous part, the posterior portion 

 much smaller than the anterior. Anal fin similarly divided in the 

 adult. Caudal peduncle slender, keeled. Ventral fins thoracic, incom- 

 plete or entirely wanting. Caudal tin widely forked in the adult. Gills 

 of peculiar structure, the lamina? of each arch joined into one plate 

 by reticulations. Gills 4, a slit behind fourth ; gill-membranes separate, 

 free from isthmus. Pseudobranchiiie present. Branchiostegals 7. Air- 

 bladder present. Pyloric coeca very numerous. Very young individuals 

 diflering much from I he adults; the tins high, both jaws prolonged into 

 a beak, and the head armed with long spines. Genera 3; species about 

 5; powerful tishes, inhabiting the open seas, most of them valued as 

 food. [Xiphiidcc Guuther, ii, 511-514.) 



a. Ventral fins entirely wanting ; teeth none. (Xiphiince) Xiphias, 209. 



aa. Ventral fins present ; teeth small. {Illfitiophorinw.) 



b. Ven tral rays united into one ; dorsal fin low Tetrapturus, 210. 



bb. Ventral rays three j dorsal very high Histiophorus, 211. 



209.— XIPMBAS Linnaius. 



Sword-fishes. 



(Linn. Syst. Nat. : type Xiphias gladius L.) 



Sword-fishes without teeth and without ventral fins. Body somewhat 

 compressed. Dorsal fins 2, the anterior beginning opposite the gill- 

 openings, falcate and elevated, its height rather less than that of the 

 body ; second dorsal very small, on the tail, opposite the small second 

 anal. In tlu? young, teeth are present and the two dorsal fins are con- 

 nected, the fin being elevated as in the species of nistiophorus. First 

 anal similar to first dorsal, but smaller, less falcate, and far behind itj 



