440 
ACTIXOPTERYGJI. 
Belonostomus ornatus, J. Felix, Palaeontogr. vol. xxxvii. (1891), 
p. 192, pi. xxviii. figs. 14-18, pi. xxx. fig. 8.—Neocomian ; 
near Tlaxiaco, Mexico. [Remains of head and scales ; 
Felix Collection, Leipzig.] 
Belonostomus pygmeeus, T. C. Winkler, Archiv. Mus. Teyler, 
vol. iii. (1871), p. 173, pi. v. fig. 1.—Lower Kimmeridgian 
(Lithographic Stone); Eichstadt, Bavaria. [Immature 
fish ; Teyler Museum, Haarlem.] 
The fragment of vertebral column from the Cretaceous of Piet- 
raroja, in the University of Naples, described under the name of 
Ophirliachis depeniitus by 0. G. Costa (Itt-iol. Foss. Ital. 1856, 
p. 14, pi. ii. fig. 4, and Atti Accad. Pontan. vol. viii. 1864, p. 107, 
pi. ix. fig. 4), may he assigned to Belonostomus. The “jaw of 
Opliisurus ? ” from Pietraroja (0. G. Costa, ibid. 1864, Append. 
p„ 126, pi. vi. fig. 6) is also probably a portion of mandible of the 
same genus. The so-called Platycerhynchus rhomheus, 0. G. Costa 
(Atti Accad. Pontan. vol. viii. 1864, p. 98, pi. xi. fig. 3), from 
Pietraroja, sometimes placed here, is based upon an indeterminable 
rostrum in the University of Naples. 
Family LEPIDOSTEIDAE. 
Head and trunk much elongated, the snout produced, and the 
abdominal much longer than the caudal region ; tail abbreviate- 
heterocercal. Cranial and facial bones robust and opercular 
apparatus complete, all more or less ganoid; mandibular suspen- 
sorium inclined forwards, but gape of mouth wide ; no presymphysial 
bone in mandible; teeth slender, conical. Branchiostegal rays 
few. Vertebral centra opisthocoelous. Fins small, the rays 
branched and articulated distally ; fulcra large. Scales rhombic, 
scarcely, if at all, deepened on the flank. 
Genus LEPIDOSTEUS, Lacepede. 
[Hist. Nat. Poiss. vol. v. 1803, p. 331 ( Lepisosteus , misprint).] 
Rostrum slightly produced in advance of the mandibular symphysis; 
preoperculum small and displaced far forwards, the suborbitals 
much divided, and the cleft of the mouth entirely in advance of the 
eye ; maxilla divided into several segments; a single spaced series 
of large teeth on the margin of the jaw, other teeth comparatively 
minute; branchiostegal rays spaced, and gular plate wanting. 
Fulcra biserial on all the fins. Pelvic fins situated about midway 
