Page:VCH Herefordshire 1.djvu/83

 PALAEONTOLOGY HEREFORDSHIRE is essentially the county of the Old Red Sandstone, which occupies nine-tenths of its area ; and, with the exception of a few from the underlying Ludlow beds, the remains of fish and fish-like creatures from this formation are the only chordate fossils (or, at all events, the only ones of any importance) found within its limits. Many of these Old Red Sandstone fossils are types either peculiar to, or first described from, the county ; while those from the Ludlow beds are the oldest of all known chordate fossils. Messrs. Salwey and R. Lightbody, of Ludlow, and Mr. G. H. Piper, of Ledbury, were among the most assiduous collectors of these fossils, especially in the well-known ' passage- beds ' between the Ordovician and the Old Red Sandstone in the cutting at the entrance to Ledbury tunnel, at the time when the Great Western Railway was in course of construction. The late Dr. Grindrod, of Malvern, was also an energetic collector, and one of the fish-like creatures from Ledbury has been named in his honour. The Rev. W. S. Symonds was another local collector after whom a species has been named. All the then known Hereford- shire chordate fossils have been noticed either by the late Professor T. H. Huxley,^ or, later on, by Professor E. Ray Lankester ; ^ but, owing to their imperfect condition and the difficulty of interpreting from such fragments the real structure of creatures so unlike any now living, many of these determina- tions have required revision. The majority of the chordate fossils from the Old Red Sandstone of the county belong to the armoured group of Ostracodermi, which is classed by some authorities among the true fishes, while by others it is regarded as forming a class by itself outside the limits of the Vertebrata. Hence it is convenient to speak of these fossils as chordates rather than as vertebrates. Other species belong, however, to undoubted fishes of the group Arthrodira, which is included in the class of Dipnoi, or lung-fishes. There are likewise a few remains of other groups of fishes, mostly in the form of spines, whose systematic position is often a matter of difficulty. It should be added that in the case of fossils from the neighbourhood of Ludlow, which is situated close to the Herefordshire border, it is often doubtful whether they were obtained from that county or from Shropshire. ' See Rep. Brit. Assoc. 1858, and Quart. Joum. Geol. Soc. xiv, 267 (1858), and xvii, 163 (1861). ' See Quart. Joum. Geol. Soc. xx, 196 (1864), and 'Fishes of the Old R;d Sandstone' {Mon. Pal. Soc. London), 1868. 35