Reviews—Prof. K. v. Zittel’s Palichthyology. WAG, 
revision is now in progress by Dr. R. H. Traquair, and three con- 
tributions to the subject have already appeared.? 
A few genera “‘incertee sedis” succeed the Placodermi, e.g. 
Menaspis, Oracanthus, Stichacanthus, etc. Of these, Oracanthus is 
now definitely proved to be an Elasmobranch ;” and all the associated 
forms, except Menaspis, will doubtless share the same fate when 
microscopically examined. 
The more typical “‘ Ganoids” are commenced with the Chondros- 
tei, of which only two families are recognized—the Acipenseridee 
and the Spatularide. Of the former, Acipenser toliapicus, Ag., is 
recorded from the London Clay of Sheppey, and we might add A. 
ornatus, Leidy, from the Miocene of Virginia? The supposed 
existence of the family Spatularide in the Devonian age (Macro- 
petalichthys) is incredible; and the recent researches of Davis‘ and 
Traquair® upon the Liassic Chondrosteus prove conclusively that 
this genus belongs to an otherwise unknown extinct family. As 
indicated by its generic name, Crossopholis possesses small pectinated 
scales, and these are worthy of note inasmuch as they necessitate the 
modification of one point in the stated family-definition. 
The Acanthodidee follow the Chondrostei, and are raised to the: 
rank of an order, without, however, any subdivision into families. 
Huxley’s conclusion is adopted. that these fishes are intermediate 
between Selachians and Ganoids; and the principal genera are 
briefly noticed. The order of Crossopterygide occupies the next: 
eighteen pages; and the first family is typified by Phaneropleuron, 
which some authors would place in the Dipnoi.. The Ccelacanthidee 
are treated mainly in accordance with Reis’ recent memoir;® and 
then follow the Devonian and Carboniferous genera included by 
Huxley in his families Saurodipterini and Glyptodipterini. The 
latter have been remarked upon lately by Dr. Traquair in the pages 
of this Macazine;’ and the most recent information concerning 
Devonian Crossopterygians will be found in this article. 
Polypterus naturally closes the systematic consideration of the 
Crossopterygian Ganoids, though no members of the Polypteride or 
Polypterini have hitherto been detected among fossils. Next are. 
placed the Paleeoniscidee and Platysomide, grouped together in an 
order named by the author, Heterocerci, and unaccountably removed: 
far from the Chondrostei, with which they are associated by Dr.: 
Traquair, whose elaborate detailed researches form the basis of the 
chapter. It is unusual, indeed, not to place the Crossopterygians 
before the Actinopterygians, as being referable to a lower stage of 
fish-evolution ; and if the definitions of ‘“‘ Chondrostei”’ and “ Hetero- 
' Guou. Mac. [3] Vol. V. (1888), pp. 508-511 (General) ; ibid. Vol. VI. (1889), 
pp. 1-8, pl. 1. (Humostews).—Ann. Mag. Nat. Hist. [6] vol. ii. (1888), pp. 485-504, 
pls. xvii. xvill. (Asterolepide). ‘ 
Gxrou. Mae [3] Vol. V. (1888), p. 85. 
Rep. U.S. Geol. Surv. Territ., vol.i. pt. i. p. 350, pl. xxxii. fig. 58. 
Quart. Journ. Geol. Soc. vol. xliil. (1887), pp. 605-616, pl. xxiii. 
Geou. Mae. [8] Vol. IV. (1887), pp. 248-257, woodcuts. 
Paleontographica, vol. xxxv. (1888). 
Grou. Mae. [3] Vol. V. (1888), pp. 512-516. 
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