62 Bulletin American Museum of Natural History. [Vol. XIX, 



It appears to have been about six feet (1.83 m.) in length. 

 The skull measured about 275 mm. Unfortunately, the right 

 preopercular and some other bones are lying on the top of 

 the skull, so that the relations of the elements were not de- 

 termined. The preopercle had a length of at least 225 mm.; 

 and at the lower end, a part of which is missing, a width of 

 about 112 mm. A quadrate has a height of 85 mm. There 

 are 53 vertebras present, but they are considerably disturbed. 

 Of these apparently 27 belong to the caudal region. The 

 neural arches appear to have been slender and not high. 

 The tail is deeply forked. The lower lobe only is present. 

 Its length is about 375 mm., but a ray near the bottom 

 of the fork is only about 90 mm. long. There are about 

 10 rays in the lobe, not including 5 rudimentary rays on 

 the front edge. The first of the latter is a lunate bone, the 

 others are slenderer and straight or irregularly bent. The 

 terminal vertebrge are not shorter than those farther for- 

 ward in the caudal peduncle and hence do not display the 

 crowded condition seen in Anogmius. There is a fan-shaped 



hypural. The pectoral fin is 



Fig. 45. Packyrkizodtis caninus Co'pe. U. 

 S. Nat. Mus. X i. Shoulder girdle, art. s., 

 articular surfaces for fin; c/., cleithrum ; cor.^ 

 coracoid; /. Ci^r., precoracoid ; /c/., pectoral 'Kacpncfc 

 fin ray; sc, scapula. UctbCUatb. 



ventral, and anal fins. The 



side is displayed from the inner surface (Fig. 45) 



long and falcate. The anterior 

 ray measures close to 595 mm. 

 It has a width of 27 mm. at 

 the base and tapers gradually 

 to the tip. It is not divided 

 or segmented. Eleven rays 

 may be counted in this fin, 

 but probably a few are miss- 

 ing. The shortest one ob- 

 served measures 135 mm. All 

 except the most anterior di- 

 vide distally into slender fila- 

 ments. At the base of the 

 fin are seen two or three 

 There appear to 

 be no remains of dorsal, 

 shoulder girdle of the left 



It is 



