A HISTORY OF STAFFORDSHIRE The ganoids, or enamel-scaled fishes, of the Staffordshire Coal Measures include a considerable number of species belonging to the primitive fringe-finned group (Crossopterygii), now represented by the bichir and the reed-fish (Polypteridae) of the rivers of tropical Africa. In the Palaeozoic family Rhizodontidae, characterized by the foldings of the walls of the base of the teeth in a manner recalling that of the labyrinthodonts, we have, in the first place, two species of the genus Strepsodus from Longton, namely S. sauroides and S. sulcidens, the former being widely distributed in the British Coalfields, while the latter is- known elsewhere from Midlothian and Northumberland. The second Staffordshire member of the family is the widely distributed Rhizodopsif sauroides, of which remains are recorded from Fenton. The allied family Osteolepididae, in which the walls of the teeth are less folded while the scales are rhomboidal (instead of cycloidal) and more fully enamelled, is represented by four species, Megalichthys bibberti, M. coccolepis, M. inter- medius, and M. pygmaeus, of which the first is very widely distributed, while neither of the others is peculiar to, or typically from, the county. Finally, in the family Coelacantbidae, characterized by the cycloidal scales and (in the fossil state) the hollow spines of the vertebrae, we have the species Cae/acanthus e/egans, which although typically from the Coalfields of Ohio, is also common in those of England. Passing on to the fan-finned group (Actinopterygii), we have among the section Chondrostei, or sturgeon-like fishes, numerous representatives of the extinct families Palaeoniscidae and Platysomatidae. Both these, it may be observed, are fully scaled types, the former characterized by the elongated, and the latter by the deep contour of the body. In the first- named of these a fish from the Deep-Mine Ironstone Shale of Longton, at first described under the name of Microconodus mo/yneuxi, has been provisionally included in the genus Gonatodus, although its real systematic position is still uncertain. To the same family belongs Cycloptychius car- bonarius, typified by a fish from the aforesaid bed at Longton, collected by Mr. Ward, and the type of the genus. The allied Rhadinicbthys is represented by the four species, R. ivardt, R. monensis, R. macrodon, and R. planti, of which the first and third arc peculiar to the county. Of the genus JLlonicbtbys, which is more nearly allied to the typical Permian Pa/aeom'scus, no less than five species have been recorded from the Car- boniferous of the county, although some of these are still imperfectly known. They are E. semistriafus, from the Knowles Ironstone Shale of Fenton, E. aitkeni, from the Lower Coal Measures and Millstone Grit of North Staffordshire, E. egertoni, from Silverdale, Fenton, Longton, and Hanley, E. microlepidotus, from Longton, and E. oblongus, from Fenton. All but the second were described from Staffordshire specimens, and the last two are known only from the county. Another species peculiar to the county is Eurylepis angtica, described in 1894 by Dr. R. H. Traquair 18 on the evidence of a specimen from the Ash Shale of Longton. 18 Ann. Mag. Nat. Hist. (6), xiv, 372 (1894). 38
