SPIRIFERID^. 



119 



Matliyrafal, near Meifod, North Wales, from which last place Prof. M'Coy also quotes it. 

 He also states that it has been also found in the green conglomerates (Lower Wenlock) 

 of Moel Seisiog, Llanrvvst, Denbighshire (but Mr. Salter refuses to acknowledge it as a 

 Wenlock species). 



Meristella ? ruRCATA, Soio. (sp.). PI. XIII, figs. 7, 8, 9. 



Terebratula furcata, J. de C. Sow. Sil. Syst., pi. xxi, fig. 16, 1839. 

 Rhynchonella — Morris. Cat. Brit. Foss., p. 146, 1854. 



— — Salter. Siluria, 2nd edit., p. 545, pi. ix, fig. 12, 1859. 



Spec. Char. Shell small, elongate-oval ; ventral valve convex, smooth, beak incurved ; 

 interior much thickened, while from under the extremity of the beak the dental plates 

 diverge widely for a short distance, and terminate anteriorly with a hinge-tooth ; from 

 thence they again converge for a short distance, leaving between them a deep concave 

 space or fissure. At the anterior base of this hollow two deep grooves commence, and 

 gradually diverge ; while a raised central ridge divides them for some distance, to become 

 itself afterwards divided into two branches, with a depression between them towards the 

 front. There exist also in the thickened lateral portions of the valve two or three oblique 

 furrows, all of which are in relief in the casts — 

 Length 4^, width 4 hues. 



Ohs. Of this species I am unfortunately acquainted with some internal casts of 

 the ventral valve only; and all my efforts to obtain a specimen showing the exterior 

 of both valves, as well as the interior of the dorsal valve, have proved unavailing. 

 Therefore our knowledge of this species, and of its true generic position, must for the 

 present be necessarily very incomplete and unsatisfactory. I have left it provisionally 

 with Meristella, as suggested by Mr. Salter, who has seen many specimens in working over 

 the collections of the Geological Survey ; but it may require to be removed hereafter, 

 when the other parts of the shell shall have been discovered. In the mean time I have 

 given carefully enlarged drawings of the interior of the ventral valve. Mr. J. de C. 

 Sowerby describes his shell as " Orbicular, very convex, smooth ; beak of one valve 

 much curved ; interior marked witli several furrows, and a forked channel in the middle." 

 This is the aspect of the cast ; the forked channel being the cast of the divided central 

 ridge. (See above.) 



Position and Locality/. This species has been obtained from the Upper Llandovery 

 sandstone, one and a half mile south of Bogmine, Shelve, Shropshire. In the Survey 

 Museum are some specimens found by Mr. Salter at Morrell's Wood, near the Wrekin. 

 Sir R. Murchison's original specimens may be seen in the Museum of the Geological 

 Society. It is, says Mr. Salter, a common species. 



