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T~. earliest scientific descriptions of fossil plants, from the rocks of New South Wales, are those by Brongniart of the genera Glossopteri8 and Phyllotheca, published in his ' ProdrSme' 1 in 1828. In his ~Hist~)ire, '2 published in the same year, figures and specific descriptions of these, and other genera, are to be found. It was not, however, until some years late~ that the first systematic collections of fossil plant-remains from this region were begun by the Rev. W. B. Clarke, Count Strzelecki, and by Dana. In 1845 Morris 3 published an account of Strzelecki's collection; and two years later McCoy 4 examined the Clarke Collection, made between 1839 and 1844, which he described in a paper in the Annals & Magazine of Natural History, in 1847. Dana's ~ specimens were described in 1849. The Clarke Collection, numbering nearly 2600 specimens of all kinds, including some 80 fossil plantremains, was, by the great generosity of its owner, presented to the Woodwardiau l-~r Cambridge, in November 1844. 8 As already stated, the more important paleeobotanical specimens in this collection were described by :McCoy in 1847, twelve being regarded as new types. It has been thought, however, that a reexamination of this early collection, in the light of the recent advancement of our knowledge with regard to the structure and I Brongniart (28) t. The numbers in parentheses after the authors' names indicate the year of publication of the work, to which reference will be found in the bibliography at the end of this paper, p. 25. 2 Brongniart (28) 2. 8 ]YIorris (45). 9 ~IcCoy (47). 6 Dana (49). 6 Clarke (78) pp. 118 & 151. Q. J. G. S. lqo. 229. B 2-~R. NEWELL ARBER ON THE CLARKE COLLECTION [Feb. ~ 9o2, affinities of fossil plants from Australia, India, South Africa, and elsewhere, might not be without value, especially as the more modern memoirs on the fossil flora of Australia, by Feistnnantel ~ and Tenison-Woods, 2 contain in several instances only the original descriptions of McCoy, without amplification. 3 The exact geological age of the beds, from which these plants were obtained, has long been disputed. We may, however, first examine the plants forming the collection, reserving for the moment the evidence which they afford of geological age. The collection may be conveniently arranged in stratigraphical order, beginning with the Wianamatta Series, followed by the Newcastle Beds, and finally the plants from Arowa. A. Wianamatta Beds.
T HE occurrence of a variety of impressions or casts of seed-like bodies in the British Coal Measures has been known since the days of John Woodward 1 ( 1729), yet at the present time there is probably no set of Coal Measure fossils which stands in greater need of systematic revision than these. The most recent list of such objects, published by Dr. Kidston a in 1894, includes only five genera with nineteen species from the whole of the British Coal Measures. Of these genera one, Carpolithus, containing nearly one-third of the total number of species, is nondescript, and amounts to little more than the word ' seed'. It is a useful term under certain circumstances, but should be regarded only as a temporary expedient. There is little doubt, I imagine, that the Coal Measure seeds which have been referred to this genus are of several fundamentally distinct types.When determining Coal Measure fossils, one frequently finds that, while there is no hesitation as to the specific assignment of a particular seed, there is often doubt as to whether such and such a species really belongs to the genus to which it has commonly been assigned, and especially whether it possesses any real morphological affinity to the other species contained therein. In my own case, however, I have found it necessary to defer any opinion on such questions until an opportunity should occur for re-investigating the grouping of Coal Measure seeds in general.In attempting this difficult task here, I am well aware that the principles on which a nomenclature should be founded are to some extent matters of opinion, and that in some cases differences of opinion are likely to arise as to matters of fact. The botanical interpretation of the features exhibited by a particular impression is sometimes by no means an easy > Woodward (1729), p. 53.• Kidston (9i).[A n nnl« of Botany, VoL XXVIII. No. CIZ. January, GArber.-A Revision of Ihe Seed Impressions of tltetask, yet it is on these grounds that a classification should be based. In my opinion one of the most fundamental distinctions among Coal Measure seeds should be founded on the symmetry. We know from the study of petrified specimens that most of these fossils belong to two distinct types, the Radiosperms and the Platysperms, as F. W. Oliver 1 pointed out in 1903.The former are symmetrical in more than two planes, the latter in only two or in a single plane. At the same time a classification based solely on symmetry is not ideal. Certain seeds, such as Trigonocarpus Parkinsoni, are radiospermic from one point of view, and platyspermic from another.Although the number of such cases is few at present, an intermediate class may have to be recognized eventually. 2 The main difficulty as regards the recognition of the type of symmetry among impressions arises, of course, from the compression which many seeds have undergone before or during fossilization. From an isolated example it may be sometimes impossible to determine whether the seed in question is radiospermic or platyspermic, especially if it be a new ...
Feistmantel (90). 2 McCoy (74), (98) ; Feistmantel (90). 3 Carruthers (72), (80) ; Feistmantel (90) ; Jack & Etheridge (92) ; Shirley (98), (02). 4 Etheridge, sen. (93) ; Etheridge, jun., & David (94). 5 Johnston (86), (88), etc. ; Feistmantel (90). 6 Feistmantel (89) ; Zeiller (96 1 ) ; Seward (97 1 ) ; Etheridge (01). 7 Arber (03). 8 Potonie (99), (00). 9 Carruthers (69) ; Zeiller (95 2 ). 10 Kurtz (94 3); Bodenbender (95), ( 96).
In the absence of any detailed knowledge of the geology of the Wyre Forest Coalfield, the area may be temporarily sub-divided into four regions. Fossil floras are described from three of these: from the horizon of the Sweet Coals in the Highley area in the north, from the unproductive beds of the Dowles Valley in the centre, and from the horizon of the Sulphur Coals of the Southern or Mamble area. On the evidence of the plants the Sweet Coal Series is shown to belong to the Middle Coal Measures, while the Sulphur Coal Series, overlying the Sweet Coals unconformably, belongs to a higher horizon, the Transition Coal Measures. The Dowles Valley unproductive measures are shown to be Middle Coal Measures, which are there over 1000 feet in thickness. The Middle Coal Measure flora of the Wyre Forest includes 55 species, of which three are new, two of them being new species of Sigillaria , and one, a new type of seed-impression. Four other plants are new records for Britain. The Transition. Coal Measure flora is smaller, but includes 20 species, of which one is a new British record. It is shown that both the Middle and Transition Coal Measures of the Wyre Forest Coalfield consist of red-grey measures with Espley rocks. In the Transition Coal Measures Spirorbis -limestones also occur. The distribution of these rocks is considered in detail.
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