570 
ACTINOPTERYGII. 
name of Ancistrodon vicentinus (loc. tit. 1883, p. 667, pi. xix. 
fig. 10)':— 
P. 5925. Five teeth of the form named Corcix fissuratus by 1- 
C. Winkler, Archiv. Mus. Teyler, vol. iii. (1874), p. 300, 
pi. vii. fig. 4, and ibid. vol. iv. (1876), p. 27, pi. ii. fig 8 - 
12; Middle Eocene, Woluwe St. Lambert, Brussels. 
Noticed as Ancistrodon fissuratus by A. S. Woodward, 
Geol. Mag. [3] vol. viii. (1891), p. 108, and identified by 
Dames with Sargus ? armatus (P. Gervais, Zool. ot l’al. 
Frang. 1852, Poiss. Foss. p. 5, pi. lxix. figs. 9, 10) from 
the French Eocene ; recorded by Dames (loc. tit. 1883, 
p. 664, pi. xix. fig. 2) as Ancistrodon armatus. 
Presented by Monsieur A. Houzeau de Lehaie, 18SJ- 
The name GlyptocepJialus radiatus is proposod by Agassiz (Poiss. 
Foss. vol. ii. pt. ii. 1844, p. 264) for the tuborculated skull of a 
supposed member of the Balistidic from the London Clay of Sheppey, 
said to have been placed in the British Museum by Kbnig and 
labelled by him Ephippus owenii. This is the head of a Siluroid 
fish already described above (p. 330) as Bucklandium diluvii. 
Family GYMNODONTIDiE. 
Trunk deepened. Maxilla fused with premaxilla; no separate 
teeth, but often dental plates imbedded in the bone of the jaw, 
these continually replaced by vertical successors. Vertebral usually 
much reduced. No spines in dorsal or anal fins. Skin usually 
with small spines or spinous bony plates, sometimes naked. 
Chiefly tropical and sub-tropical marine fishes, most of them 
surface-dwellers and capable of inflating their body by filling the 
distensible oesophagus with air. A few Tetrodonts live in large 
rivers. No clearly recognisable extinct genera arc known. 
Synopsis of Genera represented by Extinct Species. 
I. Caudal region normal. 
Each jaw with median suture at sym- 
physis, and only marginal dental 
plates ; small dermal spines without 
expanded root Tetrodon (p. 571). 
Each jaw fused at symphysis ; marginal 
and inner dental plates ; dermal 
See also Part III. p. 283. 
