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 PALAEONTOLOGY in the Barrow Lias, as at the date when Mr. Browne's book was published no Leicestershire specimens of this species were contained in either the British or the Leicester Museum. It is, however, recorded from Barrow in D. T. Ansted's Physical Geography and Geology of the County of Leicester. Plesiosaurian remains, as in other localities, appear to be much less abundant in the Leicestershire Lias than are the skulls and skeletons of the fish-lizards. The Leicester Museum is, however, in possession of a magni- ficent specimen, measuring 17 ft. across the paddles, of the skeleton of the large species known as Plesiosaurus megacephalus, which was obtained from the Ammonites planorbis zone of the Barrow Lias some time previous to the year 1851. The species is stated also to have been obtained from the pit between Barrow and Sileby. A large plesiosaur skeleton from Barrow pre- served in the Dublin Museum, measuring 1 3 ft. in length, has been assigned both to this species and to the very distinct 'Thaumatosaurus megacephalus. Of other plesiosaurian specimens, it must suffice to mention that the British Museum possesses a split slab of Lower Lias from Bennington 7 showing part of the skeleton of a small specimen of Plesiosaurus hawkinsi, and also three imperfect cervical vertebrae from Barrow, in the original matrix, which it has been suggested may be referable to a species first described from the Lias of Belgium under the name of P. dewalquii. Plesiosaurian remains are likewise recorded from the Rhaetic bone-bed in the Spinney Hills. 8 The latter formation has also yielded a bone which is probably part of the lower jaw of a species of primaeval salamander, or labyrinthodont, although its condition is too imperfect to admit of accurate identification. Undescribed specimens from the Rhaetic of Wigston pre- served in the Museum of the Geological Survey, Jermyn Street, appear also to pertain to labyrinthodont amphibians. 9 The fossil fishes of Leicestershire seem to be confined to three horizons, namely the Lower Lias, the Rhaetic, and the Coal Measures. By far the most important and interesting are those from the Lower Lias, chiefly at Barrow on Soar and its neighbourhood, since they include several types at present unknown elsewhere. Commencing with these Barrow fishes, the first on the list is Undina (?) tamrvtensu, an imperfectly known member of the group of fringe-finned ganoids (for the most part extinct), belonging to the family Coelacanthidae. Its reference to the genus Undina of which a species occurs in the corresponding formation of Lyme Regis, Dorset is only provisional, Dr. A. Smith Woodward 10 stating that the single known speci- men, which is in the British Museum and was obtained at Barrow not later than 1847, is too imperfect for definite determination. The second Barrow fish, now called Oxygnathus egertoni, although at first described as Cosmolepis, belongs on the other hand to the fan-finned group (Actinopterygii), and is included among the sturgeon-like ganoids (Chondrostei). It is classed in the Palaeoniscidae, a family characterized by the complete scaling of the body. Down to the year 1891, at any rate, this species was known only by three somewhat imperfect specimens in the collection of the British Museum. 11 Another family of the same group the Belonorhynchidae is represented by a jaw from near Barrow in the Leicester Museum assigned to Belonorhynchus ' Mentioned in Nichols' Hist, of Leicestershire,, 205. 8 Browne, op. cit. 180. 9 Ibid. 182. 10 Cat. Foss. Fish. Brit. Mus. ii, 413. Ibid. 520. 23