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PKOCEEDINGS OP THE GEOLOGICAL SOCIETY. 



[Jan. 9, 



hope beds, we have Sja. elevatus in abundance, Rhynclionella Wilsoni 

 is very plentiful ; so are Lingida Lewisii, Atrypa reticularis, and 

 Strophomena Pecten. Pentamerus galeatus is frequent ; but I have 

 not the common P. KnigJitii in mj list. 



Only a few Univalves and Trilobites are known in this locality. 



But if the limestone is poor, the Lower Lucllow shale beneath it 

 is prolific indeed. When I was there, they were bringing up the 

 grey-blue shale full of large Aviculce, of the size and shape of the 

 Pearl-oysters. There was Pleurorhynchus, nearly as large as the so- 

 called Cardium Hiberhicum ! Besides a host of ordinary Brachiopods 

 (the list of which would be only a repetition of those of the Wool- 

 hope shale) and a very few Corals and Trilobites *, there are here the 

 largest Univalves known in the Silurian rocks. Pleurotomarice of four 

 or five species, some as much as five inches long ; of Euomphalus 

 three species ; very fine Bellerophons, and the common Pteropods ; 

 Orthoeeras, of great size and of many species ; and the genera Plirag- 

 moceras, Cyrtoceras, and Lituites. 



The profusion of Cephalopods from these beds in Dr. Grindrod's 

 fine collection is wonderful. Among them is a new genus, to be added 

 to the British list, which my friend Dr. A. Fritsch f recognized as 

 one of the familiar Bohemian forms. It looks like a Lituites, and 

 would have passed for a new species of it ; but there is a slight spi- 

 rality in the whorls (not so great, however, as in several Bohemian 

 species), which betrays it. It is really a subsj)iral form belonging to 

 tbe Nautilidce, and analogous to the genus Helicoceras among the 

 Ammonite group. It is 8 or 9 inches in diameter ! 



I believe tbat the " Lucllow Bone-bed " is not found in the Tunnel- 

 section. You find it a few miles to the north, at Brock Hill and 

 also at Hales End, overlain by the Downton Sandstone. 



The plant which Dr. Hooker described J, and for which he now 

 proposes the characteristic name Paehytheca sphcerica, is the common 

 fossil in the sandstone, arid is accompanied, as at Ludlow, by plant- 

 remains and fragments of Pterygotus. 



Of the " Passage-beds," described by you in your former paper §, 

 I need not say much ; but having seen this beautiful section in your 

 company, I may be permitted to observe that I quite agree with 

 your interpretation of it. The little group of olive-coloured shale and 

 grey sandstone in which the Pish-remains are found, is exceedingly 

 like that in the larger section of the same beds at Ludlow. Of the 

 Fish-remains one is identical — the Cephalaspis Murchisoni, Egerton ; 

 the other is a new Auchenaspis, certainly distinct from the Ludlow 

 species. Your section shows just what is wanting at Ludlow — the 

 300 feet of red marls and sandstones which intervene between these 

 passage-beds and the Silurian rocks, and which definitely shut the 

 former up in the base of the Old Red Sandstone. 



* In the fewness of Trilobites this shale differs materially from the WoolhojDe 

 shale before-mentioned. 



t Keeper of the Royal Bohemian Museum, Prague — an excellent observer, 

 and an authority on European birds. We passed three weeks in the Silurian 

 region most pleasantly together. 



\ Quart. Journ. Geol. Soc. vol. ix. p. 12. § Vriil. vol. xri. p. 193. 



