presence of Pterygotus remains in the Gaspé sandstone, though these were described by Dawson as plants of the genus Selaginites [op. cit. p. 399]. Remains of Pterygotus have also been found in the lower marine Devonic Dalhousie beds of Dalhousie, N. B., in fragments which appear to have been washed seaward of their proper sites. Near Campbellton, N. B., in indurated limestones containing fish remains of probable Upper Devonic age, are also such remains, which were first noted by Whiteaves when describing the fish fauna of this locality.
Fragments, presumably of Pterygotus, have been reported from the Lower Devonic[1] of the Knoydart formation, Arisaig, Nova Scotia, where they are associated with fish remains of the genus Pteraspis and Cephalaspis.[2]
All of the occurrences referred to have been more or less particularly noticed by Clarke in Early Devonic History of New York and Eastern North America, but only that at Campbellton has furnished material adequate for description. This original material consists of a suite of three specimens, now in the Victoria Memorial Museum at Ottawa. These are a free chela, the coxa of a swimming leg and a small portion of a metastoma bearing traces of ornamentation. The chela is of slender form, straight, tapering regularly to the apex which is not preserved. The length is 50 mm, its proximal width, not counting the articulating process, is 9 mm, its distal width, at the point of fracture, about 3 mm. The ramus is but little compressed, its section irregular and convex, the greatest thickness being near the inner edge, whence the ramus abruptly narrows down to the dentate edge, and more gradually to the outer edge. The teeth are in two series, one of more numerous small sharp points, and one of larger distinctly furrowed teeth, the two
- ↑ The Knoydart formation, so named by Ami, is regarded by Fletcher as of Upper Devonic age. On the basis of the fish remains Dr Smith Woodward correlated these sandstones with the Lower Devonic Hereford beds. Further investigation will be required to fix their relation to the fish beds of Campbellton, N. B., and Migouasha, Quebec, which are now regarded as of later Devonic age.
- ↑ See Ami. Geolog. Soc. America Bul. 12: 301–12. 1901; Twenhofel. American Journal of Science, Aug. 1909; Williams, M. Y., Geol. Surv. Canada Rep't, 1911, p. 244.
