A HISTORY OF LANCASHIRE The most common plants of the Middle Measures are :— Sphenopteris furcata Sigillaria ovata trifoliolatu » remfirmn Footneri „ ^'"*'" Mariopteris murkata Lepidodendron ophiurus Pecopterh Miltom „ acuUatum AUthopterh decurrins Bathrodendron mtnutifohum „ Serlii Cordaites Nmropteris gigantea Lepldostrobus variabilis ohliqua Trigonocarpus Pariinsoni " heterophylla „ Dawsii Calamocladus equisltiformis „ Nceggeratht Calamites (Stylocalamites) Suckowii Carpolithus inflatus Sigillaria t esse I lata Some of the Middle Measure sandstones occasionally yield fine specimens of Halonia and the large leaves of Cordaites, LOWER COAL MEASURE FAUNA The fauna of the Lower Measures is quite as sharply marked ofF from that of the Middle Series as are the plant fossils, and for this reason must be dealt with separately. The lowest forms of life represented are worms, of which two species are known. The one {Arenicola carbonaria) is only known by worm burrows, and tracks, whilst the other {Spirorbis pusillus) has left a minute coiled shell. Brachiopoda are represented by Lingula cf. mytiloides. The ordinary mollusca or bivalves are most common, especially Carbonicola {olim Anthracosia), the chief species being : — Carbonicola robusta Carbonicola subconstricta „ acuta „ aquilina „ rugosa Other common forms which link these coal measures with the Millstone Grit are Pterinopecten {olim Aviculopecten) papyraceus and Posidoniella lavis and P. minor. Gasteropoda are feebly represented by a few undescribed species. Cephalopoda are chiefly found in the upper part of the measures in the roof and shales asso- ciated with the Mountain Four Feet or Bullion Mine ; the common forms are : — Gastrioceras (olim Goniatites) Listeri „ ,, carhonarium Dimorphoceras Gilbertsoni Glyphioceras [olim Goniatites) reticulatum „ „ diadema ,, „ paucilobum Sc'eral species of Orthoceras occur, but few are well defined, Orthoceras obtusum being the most marked. Crustacea are represented by several species of ostracods and by a few rare forms of malacos- traca, of which Pygocephalus Cooperi, Anthrapalamon Etheridgei, and Prestwichia rotundata are the chief. Fishes were fairly abundant in numbers and species, the remains, chiefly teeth and scales, but at times whole fishes, being found in the black shales. The commonest forms are Caelacanthus elegans, Rhixodopsis sauroides, and Strepsodus sauroides. A small amphibian, Hylonomus IVildi, has been recorded from the ' soapstone ' bed over the Mountain Four Feet Mine of Colne and Trawden. For a full list of the fauna the reader is referred to papers by the author.^ MIDDLE AND UPPER COAL MEASURE FAUNA Recent researches on the part of the writer have shown that the fauna consists of 75 genera, which include 137 species, and further work by other observers has shown that the numbers will be increased. Whilst as in the Lower Coal Measures the mollusca remained the dominant forms mainly owing to the great increase in the three genera, Carbonicola [olim Anthracosia), Naiadites {olim Anthra- coptera), and Anthracomya, the fishes show an even more pronounced development. Cephalopoda and brachiopoda only occur at one horizon, viz. the ' marine band ' at Ashton-under-Lyne and Dukinfield. 1 ' The Palaeontology of the Lancashire Coal Measures,' Trans. Manch. Geol. and Mining Soc. xxviii. 22
