A HISTORY OF WORCESTERSHIRE Strensham group, which takes its title from the village of that name east of Upton-on-Severn. From these particular beds the late Rev. P. B. Brodie succeeded in obtaining a number of insect remains of great interest/ Of the vertebrate fossils of Worcestershire by far the most im- portant are the primitive fishes of the lower portion of the Old Red Sandstone. Since, however, only a very small area of the county is occupied by this formation, the number of species of these fishes that have actually been discovered within its limits falls considerably short of those known from Ledbury and Cradley, in Herefordshire, where ex- cellent sections of these strata are exposed. On the other hand, all these Old Red Sandstone fishes may really be regarded as pertaining to the Worcestershire fauna, since it must be largely due to accident that specimens of the whole of them have not hitherto been found within its borders ; and some of the Cradley section runs into the county. Most of these fishes belong to an entirely distinct group, which ceased to exist before the close of the Paleozoic epoch, and are characterized by the head and body being enveloped in a bony cuirass, and the imperfect ossification of the internal skeleton. The group is collectively known as the Ostracodermi, but is divided into three sec- tions. Among the first section, in which the head and fore part of the body were protected by a bony shield while the hinder half of the body and tail were covered by small angular plates or scales, remains of Pteraspis rostrata have been discovered at Heightington and Trimpley, and those of P/. crouchi at the first-named place. This second section, in which the head assumes a different form, and is shaped like a bent cheese-cutter, is represented by Cephalaspis lyelli and C saliveyi in the Lower Old Red Sandstone of Heightington ; the former being typically a Scottish species, while the latter is confined to the west of England. A totally different Palaeozoic group of fish-like creatures is that of the berry- bone fishes, or Arthrodira, of which the typical representative is the well-known Coccosteus of the Scottish Old Red Sandstone. In these strange creatures the armour, which is confined to the head and fore part of the body, has the external surface like coarse shagreen ; and although there were no pectoral fins, the pelvic pair were well developed. The group is represented in the Old Red Sandstone of the county by Phlyctanaspis anglica, a species first described on the evidence of Here- fordshire specimens. Another Herefordshire Old Red Sandstone fish, Climatius ornatus, belonging to a group of primitive sharks known as Acanthodii, also occurs in the corresponding formation of the county. In the Carboniferous rocks fish remains appear to be very scarce, but a tooth from Bewdley in the British Museum indicates a pavement- toothed shark belonging to the family Cochliodontida . In the Keuper such remains are less uncommon, and the species Acrodus keuperitius, a pave- ment-toothed shark of the family Cestraciontidce, has been named on the evidence of Worcestershire specimens which occur at Pendock, Ripple, » See Brodie, Fossil Insects (1845). 30
