ACriNOPTEKYGII. 
i)2 
Chirocentrites vexillifer^ J. J. Heckel, loc, cit. vol. xi. (1856), 
p. 245, pi. ii. figs. 1, 2. llirissops vexillifer^ P. Bassaiii, 
loG. cit. 1882, p. 257 ; D. G. Kramberger, Djela Jugoslav. 
Xcything is known of the so-Q,di]le(rChirocentrites'^. cavolini from 
the Cretaceous of Pietraroja (0. G. Costa, Atti E. Accad. Sci. Xapoli, 
vol. ii. 1865, no. 16, p. 9, name only). 
Genus PORTHEUS, Coj)e. 
[Proc. Amer. Phil. Soc. vol. xii. 1872, p. 331.] 
Syn. 2Iegalodon, L. Agassiz {non Sowerby, 1829), Poiss. Foss., FeuilL 
'— ~>___1835, p. 55 (in part). 
Hypsodoii, L. Agassiz, Poiss. Foss., Feiiill. 1837, p. 104 (in 
part). 
Xiphactinus, J. Leidy, Proc. Acad. Xat. Sci. Philad. 1870, p. 12. 
A provisional name given to fragmentary remains of a genus of 
fishes, which has not yet been clearly distinguished from Cliiro- 
centrites. Supraoccipital bone bearing a conspicuous median 
longitudinal cj'est; premaxillse short and deep. Teeth confined 
exclusively to the premaxillary, maxillary, and dentary bones, all 
hollow, snbcylindric or moderately compressed, but destitute of 
sharp or serrated edges, and lodged in deep sockets; very irregular 
in size, those of the premaxilla, middle of maxilla, and anterior end 
of dentaiy relatively large. Successional teeth formed directly 
beneath the functional teeth, and no nutritive foramina on the 
inner face of the jaw below the alveolar border. All the vertebral 
centra, except a few immediately behind the bead, exhibiting two 
deep, longitudinally-extended pits on each side. Both paired fins 
with few broad and stout rays, which are very finely articulated and 
divided quite at the distal end. 
Xotes on the osteology of this genus are published by 0. P. Hay, 
Zool. Bull. vol. ii. (1898), pp. 25-54, figs. 1-16. 
Portheiis molossus. Cope. 
(?) 1870. Xiphactinus audax, J. Leidy, Proc. Acad. Nat. Sci. Philad. 
p. 12. [Fin-ray; National Museum, Washington.] 
(?)1871. Saurocephalus audax, E. D. Cope, Proc. Amer. Phil. Soc. 
Tol.xi. p. 533. 
^ 1872, Portheus rnulossus^ E. D. Cope, ibid. vol. xii. pp. 175, 333. 
(?) 1873. Xiphactinus audax, J. Leid}", Contrib. Extinct Vert. Fauna 
W. Territ. (Rep. U.S. Geol. Surv. Territ. vol. i. pt. i.), p. 290, 
pi. xvii. figs. 9, 10. 
