. A guide to the study of fishes. Fishes; Zoology; Fishes. The Ganoids 23 Woodward places these fishes with the SemionotidcB and Ha- lecomorphi in his suborder of Protospondyli. It seems preferable, however, to consider them as forming a distinct order. Order Lepidostei.—^We may place, following Eastman's edition of Zittel, the allies and predecessors of the garpike in a single order, for which Hiixley's name Lepidostei may well be used. In this group the notochord is persistent, and the vertebrse are in various degrees of ossification and of different forms. The. Fig. 13.—Mesturus verrucosus
. A guide to the study of fishes. Fishes; Zoology; Fishes. The Ganoids 23 Woodward places these fishes with the SemionotidcB and Ha- lecomorphi in his suborder of Protospondyli. It seems preferable, however, to consider them as forming a distinct order. Order Lepidostei.—^We may place, following Eastman's edition of Zittel, the allies and predecessors of the garpike in a single order, for which Hiixley's name Lepidostei may well be used. In this group the notochord is persistent, and the vertebrse are in various degrees of ossification and of different forms. The. Fig. 13.—Mesturus verrucosus Wagner. Family Pycnodontidce. (After Woodward.) opercles are usually complete, the branchiostegals present, and there is often a gular plate. There is no infraclavicle and the jaws have sharp teeth. The fins have fulcra, and the supports of the fins agree in ntimber with the rays. The tail is more or less •heterocercal. The scales are rhombic, arranged in oblique series, which are often united above and below with peg-and-socket articulations. This group contains among recent fishes only the garpikes (Lepisosteus). They are closely allied to the Palceonis- cidce, but the skeleton is more highly ossified. On the other hand they approach very closely to the ancestors of the bow- fin, Amia. One genus, Acentrophorus, appears in the Permian; the others are scattered through Mesozoic and Tertiary rocks, the isolated group of gars still persisting. In the gars the vertebras are concavo-convex, with ball-and-socket joints. In the others the vertebree are incomplete or else double-con- cave, as in fishes Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Jordan, David Starr, 1851-1931. New York, H. Holt
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