486 FISHES CHAP. 
the other hand, there are certain features in the Catopteridae 
which indicate an approach to Fishes of an altogether more modern 
Fic. 283.—Palaeoniscus macropomus. Restoration, nearly one-half nat. size. 
(From Traquair. ) 
Finally, the Chondrosteidae represent a stage in a career 
of degeneration, the climax 
of which is reached by the 
modern Polyodontidae and 
Acipenseridae. 
Fam. 1. Palaeoniscidae.’ 
—Fishes with fusiform bodies, 
short dorsal and anal fins, 
and usually with a complete 
type. 
ah ber yy investment of articulating 
Fic. 284.—Outline restoration of the skull and rhombic, rarely cy cloid, ganoid 
secondary pectoral girdle of Palaeoniscus geales (Fig. y 83). Fulera 
macropomus. an, Angular ; br.r, branchio- 
stegal rays; cl, clavicle (cleithrum) ; d, 
dentary ; d.ect, dermal lateral ethmoid ; 7, 
frontal ; z.cl, infra-clavicle ; 7.op, suboper- 
culum ; mz, maxilla ; 2, nostril ; op, oper- 
culum ; 07, orbit ; p, parietal ; p.f, pectoral 
generally present at the bases 
of the median fins, and especi- 
ally along the dorsal border of 
Ribs 
fin; p.m, premaxilla ; p.op, preoperculum ; 
p.t, post-temporal ; s.cl, supra-clavicle ; s.0, 
circumorbitals ; sg, squamosal; the single 
median bone overlying the short rostrum 
is probably a dermal mesethmoid, and the 
one intercalated between the squamosal 
the upper caudal lobe. 
are not known to be present. 
Skull invested by a very com- 
plete series of paired dermal 
bones, which in number and 
and post-temporal a supra-temporal. The 
dotted lines indicate sensory canals, (From 
ba il normal Teleostome type (Fig. 
284). The secondary upper jaw includes both premaxillae and 
large maxillae ; and, as a rule, both the dentary and splenial bones 
disposition conform to the 
1 Traquair, Monogr. Palaeont. Soc. 1877 ; Quart. Journ. Geol. Soc. xxxiii, 1877 ; 
Trans. Roy. Soc. Edinb. xxx. 1883, p. 22; Ann. Mag. Nat. Hist. (4) xv. 1875, 
Dp: 237: Smith Woodward, Mem. Geol. Sune v. VN. S. Wales, Palaeont. No. 4, 1890, 
and No. 9, 1895. 
