292 THE CARBONIFEROUS SYSTEM. 



" At p. 221 of his ' Travels/ Sir C. Lyell mentions Spirifer cristatus, 

 Sclil., S}). minimus^ Sow., and Sp. octoplicatus^ Sow,, as having been 

 found in the Lower Carboniferous limestone of Nova Scotia ; but it is 

 probable that at least two of the shells so termed — namely, Sp. cristatus 

 and Sp. octojjlicatiis, are referable to a single species. The Nova- 

 Scotian specimens of the shell under notice are all very small, none 

 of those that have come under my notice exceeding four lines in length 

 by five in width ; they exactly resemble some specimens of the same 

 species found in the Carboniferous shales of Capel Rig, East Kilbride, 

 Scotland. 



" Sir C. Lyell mentions having found this shell at Windsor, Brook- 

 field, Shubenacadie, and De Bert River, in Nova Scotia; and Dr 

 Dawson adds East River, but that it is nowhere so plentiful as in the 

 shell conglomerate of Brookfield. 



Fig. 90. — Sj)irifer cristata, Sclilotheim. Fig. 91. — Spirifer acuticostata, De Koninck. 



'■'■ Spirifer acuticostata, De Koninck (Fig. 91). 



'''■Spirifer aciiticostatus, De Koninck, ' Description des Aniraaux Fos- 

 siles qui se trouvent dans le Terrain Carbonifere de la Belgique,' 

 p. 265, pi. 17, fig. 6. 



" Shell small and transversely oval ; valves convex, and ornamented 

 with from twelve to fourteen small angular ribs. The mesial fold is 

 comparatively wide, flattened, and longitudinally grooved along the 

 middle. The sinus in the ventral valve has a small median angular 

 rib, which commences at about the middle of the valve and extends 

 to the front. Beak small, incurved ; area triangular and of moderate 

 dimensions. Length four lines, width five lines, depth three lines. 



" Upon sending a proof of the plate illustrating this paper to Professor 

 De Koninck, he wrote back that two of my figures were referable to 

 Sp. acuticostatus ; and, except in size, they certainly resemble those 

 given by the distinguished Belgian Professor. It must, however, be 

 remembered that in some specimens of Sp. cristatus, or of its Carbon- 

 iferous representative, Sp. octoplicatus, the mesial fold is flattened along 

 its middle, and even possesses in some cases a shallow groove along 

 its centre, as seen in De Koninck's Sp. acuticostatus. All these 

 modifications in British specimens have been described and illustrated 

 at pages 38 and 226 of my ' Monograph of British Carboniferous 

 Brachiopoda.' 



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