^{page 343 note *} Poissons Fossiles, vol. ii. pt. 1, p. 153.

^{page 343 note †} Fauna der Vorwelt, vol. i. pt. 3, Leipzig, 1848.

^{page 343 note ‡} Handbuch der Petrefactenkunde, Tübingen, 1852.

^{page 343 note §} On the Affinities of the Genus Platysomus, “Qu. Journ. Geol. Soc., London,” v. (1849), p. 329–332Google Scholar.

^{page 344 note *} Poissons Fossiles, vol. ii. pt. 1, p. 165.

^{page 344 note †} Ib. p. 203.

^{page 344 note ‡} Qu. Journ. Geol. Soc. London, vi. (1850).

^{page 345 note *} Dyas, Leipzig, 1861, p. 8.

^{page 345 note †} Traité de Palæontologie, 2d ed., 1854, vol. ii. p. 208.

^{page 345 note ‡} British. Palæozoic Fossils, p. 614.

^{page 345 note §} Zoologische Briefe, vol. ii., Frankfurt, 1852.

^{page 345 note ║} Beiträge zur Kenntniss der fossilen Fische Oesterreichs, Denkschr. Ac. Wien. xi. 1856.

^{page 345 note ¶} Münchener gelehrte Anzeigen., Bd. L., 1860, pp. 80-99.

^{page 345 note **} On the Affinities of Platysomus and Allied Genera, “ Qu. Journ. Geol. Soc.” 1866.

^{page 347 note *} Bd. i. 2te Hälfte, Leipzig, 1875.

^{page 347 note †} Proc. Am. Phil. Soc, May 20, 1877.

^{page 347 note ‡} Carboniferous Ganoid Fishes, part i. Palœoniscidœ, p. 41, “Mem. Palæontographical Society,” 1877.

^{page 348 note *} Poissons Fossiles, vol. i. part i. pp. 153-160.

^{page 348 note †} Short Notices of American Fossil Fishes, “Am. Journ. Sc.” xli. 1841.

^{page 349 note *} On the Ganoidei Heterocerci, “Qu. Journ. Geol. Soc. Lond.“ vi. 1850.

^{page 349 note †} On the Affinities of Platysomus and Allied Genera, “ Qu. Journ. Geol. Soc. Lond.” 1866.

^{page 349 note ‡} Description of Pygopterus Greenockii, &c, “Trans. Roy. Soc. Edinb.” 1867.

^{page 349 note §} Ganoidei Heterocerci, p. 3.

^{page 349 note ║} Catalogue of British Fossils, London, 1854, p. 339Google Scholar.

^{page 349 note ¶} Faune du Calcaire Carbonifère de la Belgique, in “ Annales du Musée d'Histoire Naturelle de Belgique,” Brussels, 1878, p. 25, pl. iii.

^{page 354 note *} Bull. Ac. Roy. Belg. xxxi. 1871, pp. 512–515, plate ivGoogle Scholar.

^{page 354 note †} Op. cit. pp. 14–23, plate ii.

^{page 358 note *} Trans. Geol. Soc. Lond., ser. 2, vol. iii. plate xii. figs. 1 and 2.

^{page 359 note *} Poissons Fossiles, vol. ii. plate i. p. 170 ; Atlas, vol. ii. plate xviii. figs. 1 and 2.

^{page 359 note †} Vol. v. (1849).

^{page 359 note ‡} Mem. Palæontographical Society (1849), plate xxvi. fig. 1.

^{page 361 note *} Ann. and Mag. Nat. Hist. (4), vol. xv. 1874, p. 262, plate xvi. figs. 1–5Google Scholar.

^{page 363 note *} Op. cit., p. 306.

^{page 363 note †} Nat. Hist. Trans., Northumb. and Durham, vol. iv. 1871, p. 414Google Scholar; also in Ann. and Mag. Nat. Hist., ser. 4, vol. ix. 1872Google Scholar.

^{page 363 note ‡} Trans. Manchester Geol. Soc. vol. i. 1841, plate v. figs. 14 and 15Google Scholar.

^{page 364 note *} Ann. and Mag. Nat. Hist. ser. 2, vol. ii. 1848, pp. 130–131. British Palæozoic Fossils, p. 616, plate 3 g, fig. 9Google Scholar.

^{page 364 note †} Ann. and Mag. Nat. Hist., July 1878, pp. 15—17.

^{page 364 note ‡} Die Ctenodipterinen des Devonischen Systems, St Petersburg, 1828, pp. 33–37, plate vi. figs. 15–22.

^{page 365 note *} Geol. Mag. ser. 2, vol. i. 1874, p. 431Google Scholar.

^{page 367 note *} Here it is, however, necessary to note that I was formerly inclined to consider the bone, which in the Palæoniscid head corresponds to that which I have above referred to the mesopterygoid element, to be metapterygoid in its nature (Carboniferous Ganoid Fishes, pt. i. Pal. Soc. 1877, p. 18.)

^{page 368 note *} Op. cit. p. 312.

^{page 369 note *} Catalogue of the Organic Remains of the Permian Rocks of Northumberland and Durham, 1848, p. 15 ; “Permian Fossils” (Mem. Palæontographical Society, 1850), p. 232.

^{page 369 note †} Op. cit. pp. 302-305, woodcut, fig. 2.

^{page 369 note ‡} Beiträge zur Petrefactenkunde, v. 1842, pp. 43–47Google Scholar.

^{page 369 note §} Dyas, p. 10.

^{page 369 note ║} Qu. Journ. Geol. Soc. xxvi. 1870, p. 627Google Scholar.

^{page 369 note ¶} Geol. Survey of Illinois, vol. iv. p. 347, PL III. fig. 1 ; Pl. IV. fig. 2.

^{page 369 note **} Ann. and Mag. Nat. Hist. (4) ix. 1872, p. 252Google Scholar.

^{page 370 note *} This is probably the same specimen from Derbyshire, “ in the Jermyn Street collection,” to which Professor Young refers (op. dt. p. 305), in support of his statement that P. striatus is common to the Carboniferous and Permian formations.

^{page 370 note †} Carboniferous Fossils of the West of Scotland, Glasgow, 1871, p. 75Google Scholar. Catalogue of the Western Scottish Fossils, “British Association Guide Books,” Glasgow, 1876, p. 64Google Scholar.

^{page 376 note *} “ Ueber die Wirbelsäule fossiler Ganoiden,” Sitzungsb. der Wiener Acad. 1850, Abth. 2, p. 363.

^{page 381 note *} “Münchener Gelehrte Anzeigen,” 1860. Dr Wagner here uses Quenstedt's name Pleurolepis for Tetragonolepis of Bronn, and Tetragonolepis for Æchmodus of Egerton, Ædimodus is distinguished from Dapedius, De la Beche, only in having the apices of the teeth simple instead of bifid ; but as Sir Philip Grey-Egerton has himself pointed out, both forms of tooth may occur in the same specimen, and the name Æchmodus is therefore not maintainable. As to the use of “ Pleurolepis,” its priority over Tetragonolepis cannot be maintained. It is true that Quenstedt first pointed out that Tetragonolepis semicinctus, Bronn, was generically distinct from the other species added by Agassiz to the same genus, but surely, instead of inventing a new name for the first, and passing Tetragonolepis on to the others, he ought to have preserved the original generic name for the original type.

^{page 381 note †} The restored figure of the head of “Æchmodus,” given by Professor Young in his paper “ On the Affinities of Platysomus,” is incorrect in at least one important particular, namely, in representing the parietals as pushed outwards to a position behind the squamosals by an intruding compound “ supraoccipital.” The plate, which he has lettered as “post-frontal,” seems to me to be only a member of the circumorbital ring.

^{page 384 note *} Besides Agassiz's “ Poissons Fossiles,” the following works may be consulted in connection with the structure of the Pycnodontidæ :”

Grey-Egerton, , Sir, Philip. “On the Affinities of Platysomus.” Qu. J. Geol. Soc. v. 1849Google Scholar.

DrWagner, A. “ Beiträge zur Kenntniss der in den lithographischen Schiefern Bayerns abgelagerten urweltlichen Fische.” Abh, Bayer. Ac. vi. 1850.Google Scholar

DrWagner, A. “Monographie der fossilen Fische aus den lithographischen Schiefem Bayerns,” pt. i. Abh. Bayer. Ac. ix. 1861.Google Scholar

Victor, Thiollière. “Poissons Fossiles du Bugey,” pt. i. Paris, 1854Google Scholar.

Heckel, J. J. “ Beiträge zur Kenntniss der fossilen Fische Oesterreichs.” Denkschr. Wien. Ac. xi. 1856Google Scholar.

Quenstedt, F. A. “ Handbuch der Petrefactenkunde,” second ed. Tübingen, 1867Google Scholar.

^{page 389 note *} I have already (Mem. Palæontogr. Soc, 1877) stated my reasons for placing the Palæoniscidæ and consequently also the Platysomidæ rather in the Acipenseroid than in the Lepidosteoid suborder of Ganoids. To reopen this question is, however, beyond the scope of the present essay.