SPIRIFERIDtE. 



103 



It occurs in the Island of Gothland ; and was found by M. Barrande in the Silurian 

 rocks of the neighbourhood of Prague, in Bohemia, where the shell attained larger dimen- 

 sions than it appears to have ever had in England or Sweden. 



Palaeontologists have, in various works, described as Spirifers several other shells 

 that I find do not belong to the genus, and which will be found under other names in 



Pentland Hills are regarded by Sir Roderick as Upper Silurian, and some of them are probably of 

 Wenlock age. Further examination of the tracts on the North Esk and Lyne Water showed that at 

 places these Silurian rocks are richly fossiliferous. I made a considerable collection, which was after- 

 wards largely increased by the labours of Mr. Salter and Mr. R. Gibbs. The result of these researches 

 went to show that, at least, the upper portion of the Silurian series of the Pentland Hills is of the age 

 of the Ludlow rock ; while certain red sandstones and conglomerates overlying the olive-coloured fossili- 

 ferous beds were held to mark the base of the Old Red Sandstone. 



" The following is the section, in descending order, as far as the disturbed character of the strata 

 will allow it to be made out. Red conglomerates, sandstones, and shales = Base of the Lower Old 

 Red Sandstone (?). 



"3. Olive and brown sandy shales, sandstones, and mudstones, some of the beds full of Ludlow 

 fossils. 



" 2. Hard sandstone and beds of quartzose grit, containing among other obscure shells, Orthonota 

 amygdalina, Mytilus, Avicula, a shell like Platijchisma simulans, Orthoceras, and numerous 

 fragments like Fish plates or scales. 



"1. A thick series of green, grey, and reddish shales, with bands of hard grit and sandstone, contain- 

 ing in some places abundant remains of Dictyocaris. 



" The basis of this series is concealed under the conglomerates of the Middle (?) Old Red Sandstone 

 series ; but the whole visible thickness of the Upper Silurian rocks was estimated by me to range between 

 3000 and 4000 feet. In this mass of strata, while the upper portion is undoubtedly of Ludlow age, there 

 is room also for the representation of the V»''enlock Rocks." 



Subsequently to Mr. Geikie's researches, several members of the Geological Society of Edinburgh, 

 among whom we may more particularly name \Messrs. G. C. Haswell, D. J. Brown, and J. Henderson, 

 have devoted much time to the study of these beds and to collecting their fossils ; and I had the 

 pleasure of visiting the locality during the spring of 1866. Mr. Haswell has also, in an interesting little 

 brochure, 'On the Silurian Formation in the Pentland Hills ' (1865), given us a description of the locahty, 

 and of many of its fossils. He is of opinion that it is in the " Mudstone H " of his map, in Deer-Hope 

 Burn, and belonging to the Wenlock period, that the greatest number of Brachiopoda occur ; while, in the 

 upper beds (at "I " of his map, and on the same stream), referable to the Ludlow, the only Brachiopods 

 hitherto found are Rhynchonella Pentlandica, Spirifera crispa, and Lingula lata. 



The following is a list of the species of Brachiopoda I have been able to determine from these beds. 

 They have been collected by the gentlemen above named ; and in an interesting paper read by Messrs. 

 Brown and Henderson to the Geological Society of Edinburgh, will be found some new and important 

 matter in connection with the distribution of these fossils. 



Lingula lata, Sow. ; Discina rv.gata (?), Sow. ; Crania implicata, Sow. ; Spirifera crispa, His. ; 

 Sp. (Cyrtia) exporrecta, Wahl. ; Meristella tumida, Dal. ; M. (?) Maclareni, Haswell ; Athyris compressa. 

 Sow.; Nucleospira pisum, Sow.; Atrypa reticularis, Liu.; Rhynchonella Pentlandica, Haswell; Rh. 

 Wdsoni, Sow. ; Rh. nucula, Sow. ; Rh. crispata (?), Sow. ; Orthis elegantula, Dai. ; O. biloba, Lin. ; 

 O. Lewisii, Dav. ; O. calligramma. Sow. (?) ; O.? minuta, Haswell; Strophomena applanata, Salter; 

 St.pecten,lAnu.; St. antiquata, Sow. ; St. rhomboidalis, Wah]. ; St. Walmstedti, Lindstrom; Leptana 

 transversalis, Dal. ; and Chonetes striatella, DaL 



