598 
ACTINOPTEEYGII. 
small. Both paired fins present, usually well-developed. Dorsal 
fin occupying nearly the whole of the back, simple or more or less 
subdivided into two or three parts ; one or two anal fins ; caudal 
fin separate, or if united with other median fins, the dorsal with a 
separate anterior portion. Scales small and cycloid. In the recent 
forms:—air-bladder and pyloric appendages usually present; pseudo- 
branchise absent, or glandular and rudimentary. 
This family dates back to the Upper Eocene, but only one extinct 
genus is recognisable. The “ cod-fishes ” and their allies of the 
present day chiefly inhabit the seas of the north temperate and 
arctic regions, often descending to great depths. Only one genus 
{Lota, Cuvier) occurs in freshwaters. 
A figure of the skeleton of Lota is published by Agassiz, Poiss. 
Boss. vol. V. pi. H. A detailed description of the osteology of Gaclus 
a^glejlnus is given by H. St. John Brooks, Proc. Boy. Dublin Soc. 
n. s. vol. iv. (1884), pp. 166-196, pis. v.-ix. 
Genus NEMOPTERYX, Agassiz, f ( i 
[Poiss. Boss. vol. V. pt. i. 1844, p. 75.] 
Syn. Palceogadus, G. vom Batb, Zeitschr. deutsch. geol. Ges. vol. xi 
1859, p. 126. ^5-7^ 
Trunk elongal& and laterally compressed, slightly tapering 
behind. Margin of jaws with a single spaced series of large, 
recurved, pointed teeth. Pectoral fins much enlarged; pelvic fins 
small. Dorsal fin almost or completely subdivided into three 
acuminate portions, anal fin into two similar portions; caudal fin 
ro 
separate, truncated or rounded behind. 
Nem^teryx tro^<fheli (vom Bath). 
1836. Cyclurus crassus, P. M. G. Egerton, Phil. Mag. vol. viii. p. 368 
(name only). 
1836. Cyclurus nemopteryx, P. M. G. Egerton, ibid. p. 368 (name only), 
1842-43. Nemopteryx o'assus, L. Agassiz, Poiss. Foss. vol. v. pt. i. 
pp. 6, 75, pi. xxii. [Distorted fish; British Museum.] 
1842-43. Nemopteryx elongatus, L. Agassiz, ibid. pp. 6, 76, pi. xxi a. 
[Distorted fish ; British Museum.] 
1859. Palceogadus troschelii, G. vom Bath, Zeitschr. deutsch. geol. Ges, 
vol. xi. p. 126, pi. V. fig. 3. 
1859. Palceohrosmius elongatus, G. vom Bath, ibid. p. 130. 
1886. Nemopteryx troscheli, A. Wettstein, Fischfauna d. Tertiaer. Glar- 
nerschief. (Denkschr. schweiz. Pal. Ges. vol. xiii.), p. 59, pi. iv. 
