534 Dr. S. Woochcard — Discovery of Trilohites 



EXPLANATION OF PLATE XVII. 



Britisli Museum 

 Figs. 1 and 2. Aporrhdis Jirma, sp. nov. Brockenhurst. (Natural History). 



,, 3 and 4. A. triangulata, sp. nov. Heme Bay. ,, ,, 



,, 5 and 6. A. Soiverhii, Mantell. Clarendon. ,, ,, 



„ 7 and 8. A. Slargerini, He 'Konmc\. Heme Bay. „ ,, 



,, 9 and 10. A. Bowerhankii, Morris. Eeculvers. ,, ,, 

 AU drawn natural size. 



II. — On the Discovery of Tkilobites in the Culm-Shales of 



South-East Devonshire.^ 



By Henry Woodward, LL.D., F.R.S., F.G.S. 



ALTHOUGH the ' Culm,' or Carbonaceous series, of Devonshire, 

 has long been known and studied, it has been a matter of con- 

 siderable doubt as to the exact horizon in the Carboniferous forma- 

 tion with which it may properly be correlated. 



The Geological Surveyors have, it is true, spent much time in 

 re-examining certain parts of the County ; but, owing to the smallness 

 of the scale of the Ordnance Survey Map (only one inch to the mile) 

 and the inaccuracy of the topography, but little detailed work could 

 be done. 



Prof. J. Beete Jukes, F.R.S. (Quart. Journ. Geol. Soc. 1866, pp. 

 320-371), and subsequently Mr. E. Etheridge, F.R.S. {op. cit. 1867, 

 pp. 568-698), described the whole of the northern portion of the 

 county afresh, whilst Messrs. Horace B. Woodward, Clement Eeid, 

 and W. A. E. Ussher, as representing the Geological Survey, have 

 been engaged upon certain parts in both the northern and southern 

 areas. Added to this, Dr. Harvey B. Holl, F.G.S., Mr. A. Champer- 

 nowne, F.G.S. , and Mr. John E. Lee, F.G.S. , have contributed not 

 a little to the elucidation of difficult parts of the Geology of Soutli- 

 Eastern Devon, whilst Mr. Townshend Hall, F.G.S., has done equally 

 useful work in the Northern area. 



In 1839 Sir H. T. de la Beche^ notices the Culm-formation, and 

 mentions that Prof. Phillips regarded the Shale-fossils as belonging 

 to the Carboniferous Limestone. The list of plants which he gives 

 contains a mixture of species, many being in all probability true 

 Coal-measure plants from Somerset, which do not occur in the Culm.^ 



In studying the Culm-measures near Chudleigh, De la Beche sup- 

 posed that the Culm-shales dipped beneath the Devonian Limestone, 

 in consequence of which he was led to include this Limestone in the 



1 See Plate XVI. (in November Number), Figures 6 to 11, pp. 484-489. 



^ Eeport on the Geology of Cornwall, Devon, and West Somerset, 1839, pp. 110, 

 145, and fig. 8, pi. iv. See also Trans. Geol. Soc. 2nd series, vol. iii. p. 163. 



3 Mr. R. Kidston, F.G.S., in reply to my inquiry, gives me the following species 

 as determined by him from the Culm : 



Asterocalamites scrobicnlatus, Schlot. sp. 



{ = Bornia radiata, Brong.) 

 Calaniites Roemeri, Gbpp. 

 Sphenopteris, sp. nov. 

 Lepidodendron Mhndeanum (?) 



LepidopMoios, sp. 

 Halonia (fruiting branch of 



LepidopMoios) 

 Sigillaria (?) 

 Stigmariajicoides, Brong. 



(To these I may add Ladoxylon, Sternb. {Sternbergia) , in Mr. Vicary's collection.) 

 All these plants have (says Mr. Kidston) a " Calciferous Sandstone" facies and are 

 equivalent to the " Culm " of Germany, i . 



