2. Revision of the Fauna of the Bokkeveld Beds.-By F. R. (With Plates IV-XI.) INTRODUCTION. SINCE the publication of the descriptions of the Trilobita, Brachiopoda, and Mollusca of the Bokkeveld Beds by Mr. P. Lake* and the author † in the Annals of the South African Museum about twenty years ago, a considerable amount of fresh material has been collected. Some of it was described by the author in a supplementary paper in the Annals in 1908, and in another communication to the Geological Magazine in 1906,§ while in the latter year Professor Schwarz || dealt with some specimens in the Albany Museum and described several new species. The present author reviewed the whole fauna and its relations in 1907,¶ and gave a list of references to papers concerning it up to that date. The great progress which has been made during recent years in our knowledge of the Devonian faunas of the South American continent has led to their closer comparison with the fossils of the Bokkeveld Beds, and Thomas,** Knod,†† Clarke,‡‡ and * Lake, "The Trilobites of the Bokkeveld Beds," Ann. S. Afr. Mus., vol. iv, pt. 4, No. 9, 1904, pp. 201-220, pls. xxiv-xxviii. † Reed, "Brachiopoda from the Bokkeveld Beds," ibid., vol. iv, pt. 3, No. 7, 1903, pp. 165-200, pls. xx-xxiii ; "Mollusca from the Bokkeveld Beds," ibid., vol. iv, pt. 6, No. 11, 1904, pp. 239-272, pls. xxx-xxxii. Reed, "New Fossils from the Bokkeveld Beds," ibid., vol. iv, pt. 8, No. 14, pp. 381-406, pls. xlvii, xlviii. § Reed, "New Fossils from the Bokkeveld Beds," Geol. Mag., Dec. v, vol. iii, 1906, pp. 301-310, pls. xvi, xvii. 66 || Schwarz, South African Palaeozoic Fossils," Rec. Alb. Mus., vol. i, pt. 6, 1906, pp. 347-404, pls. vi-x; Reed, Geol. Mag., Dec. v, vol. iv, 1907, pp. 34-36. ¶ Reed, "Fauna of the Bokkeveld Beds," Geol. Mag., Dec. v, vol. iv, pp. 166–171, 222-232. ** Thomas, Zeitschr. deut. geol. Gesell., vol. lvii, 1905, pp. 233–290, pls. xi-xiv. †† Knod, Neues Jahrb. f. Miner. Geol., Beil. Bd. xxv, 1908, pp. 493-600, pls. xxi-xxxi. Clarke, "Fosseis devonianos do Parana," Mon. Serv. Geol. Miner. Brasil, vol. i, 1913, pp. 1-353, pls. i-xxvii. Kozlowski* have paid special attention to this matter, while further material from the Falkland Isles has been studied by Newton † and Clarke. It seemed, therefore, to the author that a revision of the South African material was desirable as well as an examination of the large number of new specimens which had been added to various museums. Accordingly, during a visit in 1924 of six months to South Africa, a detailed study was made of the collections in the museums at Cape Town, Pretoria, Bloemfontein, Grahamstown, Kimberley, and Stellenbosch, in each of which a rich series of fossils is preserved, while the smaller collections in the Port Elizabeth, Maritzburg, Durban, and Buluwayo Museums were also examined. To all those who afforded me the facilities for working at these collections and gave me much assistance in the task, my hearty thanks are due. The author himself was also able to study to some extent the beds in the field and to collect specimens in the districts of Ceres and De Doorns through the kindness of the farmers and others in those parts. The old collections in the British Museum which Salter and Sharpe described, together with the recent additions, have been re-examined, and some new material in the Sedgwick Museum, Cambridge, from the Bokkeveld Beds has also been studied. The comparison of many of the fossils with those from corresponding beds in South America has been rendered easier by the presence of a representative series from the Falkland Islands in the Albany Museum, Grahamstown, and of specimens from Brazil in Dr. A. L. du Toit's collection in Cape Town. In those cases in which the synonymy of the species has been previously given by Mr. Lake or the author in their descriptions of the fossils in the Annals of the South African Museum, 1903-08, and is still accepted as correct, it is not repeated, but where modifications of the views there expressed have been made, a new list of synonyms and references is given. We cannot avoid expressing the opinion that many of the species of South African and South American Devonian fossils rest on somewhat insecure foundations, and in some cases it would have been better if no new specific names had been used. For there is often much doubt as to the true characters of the specimens, the types being in a poor or unsatisfactory state of preservation, and even the critical generic characters are sometimes not shown. * Kozlowski, "Fossiles devoniennes de Brésil," Ann. de Paléont., vol. viii, 1913, pp. 1-19, pls. i-iii ; "Foss. Devon. Bolivie," ibid., vol. xii, 1923, pp. 1-112, pls. i-x. † Newton, Proc. Roy. Phys. Soc. Edinburgh, vol. xvi, 1906, pp. 248-257, pl. x. Difficulties also arise from want of agreement as to which examples should be regarded as typical, so that the views of authors frequently differ widely as to the limits of the species or the identity of African and American forms. Such obstacles are met with especially in the case of the older established Bokkeveld species, and render a comparison of the fossils less precise than could be wished. But, on the whole, the close resemblance of the Devonian faunas from opposite sides of the South Atlantic is a most noteworthy and conspicuous feature, and the detailed analysis of the Bokkeveld fauna brings out this similarity to a striking extent. From the fact that the author was fortunate enough to discover several new species and even genera which had not been previously recorded from the Bokkeveld Beds, in the course of his brief visits to certain exposures near Ceres and De Doorns, it is extremely probable that many more additions will have to be made in the future to the fauna of these beds when collecting is more thoroughly and extensively done. Moreover, when Dr. W. K. Spencer has finished his investigation of the Asteroidea, there will be several new forms to be added to the list of fossils, though as yet he is unable to furnish me even with generic names. The present list of species cannot, therefore, be considered final or exhaustive, but so far as existing material allows it is as complete as possible. ACTINOZOA. Zaphrentis? zebra, Schwarz. 1906. Zaphrentis zebra, Schwarz (pars), Rec. Albany Mus., vol. i, No. 6, p. 360, pl. vii, fig. 12 (1586 Alb. Mus.). The specimen from the Cockscomb Mountains which Schwarz figured as Zaphrentis zebra is in the condition of a distorted internal cast, and therefore not in a satisfactory state of preservation for determination, and even the genus is doubtful. Schwarz's definition is therefore unavoidably incomplete, and it does not apply strictly to the second specimen (1587 Alb. Mus.) which he mentions (but does not figure) under the same name. Corals are extremely rare in the Devonian beds of the Southern type, and of simple forms Kozlowski* is the only author who * Kozlowski, "Faune Dev. Bolivie," Ann. Paléont., vol. xii, 1923, p. 97, pl. x, figs. 5-7. |