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BRITISH CARBONIFEROUS BRACHIOPODA. 



Loc. In England A. planosnlcata has been collected in the lower dark Carboniferous 

 limestone of Lovvick, in Northumberland ; at Longnor, in Derbyshire ; at Bolland ; Settle ; 

 and in several other localities. In Scotland it has been met with in Lanarkshire, but 

 is most abundant in Ireland, whence Mr. Kelly furnishes us with the following localities : 

 Blacklion, Millecent, Little Island, Milverton. On the Continent it has been found by 

 M. de Verneuil and De Koninck in the Carboniferous limestone of Vise, in Belgium. 



Athyris expansa, Phillips. PL XVI, figs. 14, 16—18 ; PI. XVII, figs 1.— 5. 



Spirifera expansa, Phillips. Geol. of Yorkshire, vol. ii, p. 220, pi. x, fig. 18. 

 Atrypa expansa, /. de C. Sow. Min. Con., pi. dcxvii, fig. 1 (the upper three large speci- 

 mens only), 1840. 

 — fimbriata. Ibid., fig. 4 (not Sp. fimbriata, Phillips). 

 Athyris expansa, M'Coy. British Palaeozoic Fossils, p. 433, 1855. 



Spec. Char. Transversely elliptical, always very much wider than long ; valves evenly 

 and equally convex, often much depressed, with or without a gentle mesial depression in 

 the ventral valve, no fold in the dorsal one ; beak small, incurved ; foramen circular and 

 contiguous to the umbone of the opposite valve. External surface of both valves covered 

 with fine, indistinct radiating lines or striae, departing from the extremity of the beaks, 

 and crossed by numerous concentric lines or ridges of growth. The spiral appendages 

 occupy the larger portion of the interior. Dimensions very variable ; three specimens 

 measured — 



Length 21, width 27, depth 11, without the lamellar appendages. 

 16, „ 22, „ 8, ditto. 

 „ 10, „ 29, „ 6, ditto. 



Obs. This species appears to be more variable in shape than A. planosulcata, 

 from which it may be usually distinguished by its very transversely elliptical form, 

 some specimens being almost twice and a half as wide as long (figs. 17, 18) ; and is often 

 found in different states of malformation (PI. XVII, figs. 2 — 4). The external surface is 

 marked by faint radiating lines, which, according to Mr. J. de C. Sowerby, are inter- 

 sected by u broad striated imbricating fringes," and of which a representation is given 

 in pi. dcxvi, fig. 1, of the ' Mineral Conchology.' It is probable that these lamelliform 

 prolongations were very similar to those of A. planosulcafa ; but as they were not 

 present on any of the numerous individuals that came under my direct observation, 

 I have contented myself with reproducing the statement made in the ' Mineral Con- 

 chology.' 



Ter. fimbriata (Phillips) has been classed by some palaeontologists among the synonyms 

 of A. expansa, but although the author of the' Geology of Yorkshire' has omitted to furnish 



