THE SWORD-FISH. 215 



having nine finlets above and below, and no abdominal 

 bands. 



Genus X1PHIAS. — Dorsal fin one ; ventral fins want- 

 ing; snout produced into a long sword-like process. 



XlPHIAS GLAD1US,* The SwOKD-FISH. 



Description. — " Body elongated, nearly round posteriorly, a little 

 compressed in front ; depth increasing with the age, from one- tenth 

 to one-sixth of the entire length, reckoning this last from the end of 

 the sword to the extremity of the lobes of the tail ; sword three- 

 tenths ; upper part of the head vertical ; eye round ; its diameter 

 nearly two-thirds of the breadth of the cranium above it ; sword ter- 

 minating in a sharp point ; the edges cutting, and finely denticulat- 

 ed ; lower jaw likewise pointed, extending to where the upper sur- 

 face of the sword becomes horizontal ; no teeth in either of the jaws ; 

 pharyngeans only with fine teeth, like shorn velvet ; no true tongue ; 

 gill-opening large ; the branchiostegous membrane with seven rays ; 

 pectorals inserted very low down, sickle-shaped, one-seventh of the 

 entire length, this last being reckoned as before ; ventrals none. 

 Dorsal commencing over the gill-opening, and extending in young 

 subjects to within a short distance of the caudal, its anterior portion 

 very much elevated and pointed ; rays rapidly decreasing from the 

 fifth to the eleventh, continuing low beyond that point to the thirty- 

 ninth or fortieth ; last three or four again elevated ; all the interme- 

 diate or low portion of the fin extremely delicate, and with the rays 

 more slender than those at the two extremities ; in adult individuals 

 often found very much torn, or even entirely destroyed, causing the 

 two elevated ends which are left to appear like two distinct fins ; anal 

 somewhat similar in shape to the dorsal, but much shorter, only com- 

 mencing in a line with its last third portion ; caudal crescent-shaped ; 

 the whole head and body covered with a somewhat rough skin, the 

 roughness arising from very minute scales ; opercule smooth ; lateral 

 line scarcely visible ; on each side of the tail a projecting horizontal 

 keel ; number of vertebrae, twenty-five. Colour of all the under 

 parts, fine silvery white ; upper parts tinged with dusky blue. Young 

 individuals, from twelve to eighteen inches in length, have the whole 

 body covered with little tubercles, disposed in longitudinal rows ; 

 these disappear first on the back, and afterwards on the belly ; tliey 



* Xiphias ffladius, Ouv., Yar., Jen., Linn., Pen., Flem. 



24 



