60 CARBONIFEROUS TRILOBITES 



Physical Structure of Devonshire, and on the Sub-divisions and Geological Rela- 

 tions of the Older Stratified Deposits," 1 devote pp. 669 — 684 to a consideration 

 of the " Culmiferous Series, its Relation to the other Formations, Structure, and 

 Fossils." They mention (p. 678) that " in Ugbrook Park, near Ohudleigh [in close 

 proximity to Waddon-Barton, where the Trilobites were discovered by Mr. Lee], 

 there is a large development of Culm Sandstone as coarse as Mill-stone grit, and 

 passing into a conglomerate form ; over it are some beds of more thin-bedded grey 

 sandstone, not to be distinguished from a Coal-Measure sandstone, and containing 

 very fine vegetable impressions, among which are well-marked Galamites. Indeed, 

 through the whole of the upper group we are describing, vegetable impressions, 

 though rarely so perfect as to give anything like specific characters, are extremely 

 abundant." They add, " All the beds are intersected by numerous open joints, 

 which in the coarser contorted beds are very irregular in their directions. But 

 when the beds have a finer flaggy or shaly structure, the joints often become 

 parallel (especially in a direction nearly transverse to the strike) so as to separate 

 the strata into prismatic masses " 2 (p. 679). 



" Among the more calcareous bands some are fossiliferous, containing a great 

 abundance of at least two genera of bivalve shells; one a Posidonia" (Posidonomya 

 Becheri, Bronn) the other of a genus not ascertained, but regarded as a marine 

 shell. " In the same part of the series are Goniatites of at least two species, both 

 of which are unquestionably marine, and (according to Professor Phillips) identical 

 with Goniatites of the Yorkshire Coal-field." 



After quoting Prof. Lindley's determinations of the Plants (pp. 681 — 682), 

 the authors conclude : " On the whole, considering that the culmiferous rocks of 

 Devon form a distinct group, with a peculiar mineral type (unlike the older groups, 

 but nearly resembling the culmiferous beds of Pembrokeshire) — that they overlie 

 all the other groups, and are overlaid by no rock newer than the New Red Sand- 

 stone — that, notwithstanding the paucity of fossils in the black limestone (in which 

 respect it resembles the ' calp ' of Ireland), there are in it one or two species not 

 separable from known Mountain Limestone fossils, and, finally, that the flora of the 

 Upper Culms, as far as it has been ascertained, agrees specifically with the known 

 flora of the Carboniferous period ; we think we have strong direct evidence to 

 establish our position, " that the Upper Culm Strata of Devon are the geological 

 equivalent of the ordinary British. Coal-fields." 



1842. — Mr. R. A. C. Austen, 3 whose paper was read December 13th, 1837, 

 describes the culmiferous deposits of the South-East of Devonshire, and particularly 



1 ' Trans. Geol. Soc. Lond.,' second series, vol. v, 1840 {read June 14th, 1837). 



2 This paragraph gives a very exact description of the lithological characters of the heds at 

 Waddon-Barton by Chudleigh, containing the Culm Trilobites. 



3 'Trans. Geol. Soc. Lond.,' 1842, 4to, second series, vol. vi, "On the Geology of South-East 

 Devonshire." 



