468 TELEOSTEI 



dorsal often of huge size. The upper jaw is produced into a long spear- 

 like ' sword.' The teeth are small, the air-bladder large and sacculate, 

 the scales elongate. About twenty-four vertebrae. The pelvic fins are 

 reduced, having only one to three dermal rays. 



Xiphiorhynchus, van Ben.; Ancestrus, A. S. W. Eocene, Europe. 

 Histiophorus, Lac. (Fig. 497) ; warm seas; Eocene, Europe. Tetrapterus, Raf. 



FIG. 497. 

 Histiophorus pulchellits, C. and V. (After Gujitlier.) 



Family XIPHIIDAE : The Sword -Fish, has twenty -six vertebrae, no 

 teeth, a very long flattened rostrum formed chiefly by the upper jaw, 

 and 110 pelvic fins. The young have both teeth on the jaws and granula- 

 tions in the skin. 



Xiphias, Art. ; world-wide range. 



TRIBE 7. KURTIFORMES. 



This tribe contains a single aberrant genus, Kurtus, witli a short 

 dorsal and long anal fin, each having a few small spines ; pelvic fins 

 thoracic in position, and provided with one spine and five jointed rays ; 

 and small pectorals supported by four radials on the coracoid. The 

 scapula is absent. Most of the ribs are fixed to the ossified wall of the 

 air-bladder. There is no subocular shelf, and the occipital crest is 

 developed into a remarkable hook-like process. Minute scales cover the 

 compressed body. The teeth are villiform. 



Family KURTIDAE. Kurtiis, Bl. ; Indian and Pacific Ocean?. 



Subdivision 3. ZEORHOMBIFORMES. 



In this group are placed the asymmetrical Flat -Fish, and two 

 families supposed to represent remnants of the symmetrical ancestral 

 forms which gave rise to them. The body is always much com- 

 pressed, and very deep ; the dorsal and anal fins are elongate ; the 

 abdominal region is shortened and the caudal lengthened ; the 

 caudal fin is normal, without, however, the spine usually found on 

 the side of the hypural bone ; and the pelvic fins have from seven 

 to nine dermal rays. Transverse purapophyses, pleural ribs, and 



