318 BRITISH SILURIAN BRACHIOPODA. 



form it resembles L. Ilumboldtii, De Verneuil ; but if'has the ventral valve less convex, 

 the cardinal area narrower, and the radiating striae slightly different. 



Position and Locality. I found several examples of this shell at Benthall Edge, near 

 Iron-Bridge, in Wenlock Limestone. 



Genus — LepTjENA, Dolman. 

 (See 'General Introduction,' p. 108.) 



The species composing this genus (or sub-genus) are more or less semicircular, and 

 concavo-convex or involute. It is distinguished from Stropliomena by the large, elongated, 

 thickened muscular impressions in the dorsal valve, as seen in such species as Leptcena 

 transversalis, L. sericea, L. tenuicincta, &c. ; and the valves are usually finely striated. 

 The species are not nearly so numerous as those of Stropliomena ; but it is a widely 

 spread genus. 



Lept.^na transversalis, Wahlenherg. PL XLVIII, figs. !• — 9. 



Anomites transversalis, Wahl. Acta Upsal., vol. viii, p. 64, No. 4, 1821. 

 Lept^na — Dolman. Vet. Akad. Handl,, p. 109, pi. i, fig. 4, 1828. 



— — Sisinger. Lethsea Suecica, p. 69, pi. xx, fig. 5, 1837. 



— — Von Buck. Ueber Delthyris, &c., 1837 ; and Mem. Soc. 



Geol. France, vol. iv, p. 222, pi. xii, fig. 25, 1840. 



— ^ J.de C. Sow. Sil. Syst., pi. xiii, fig. 2, 1839. 



— DT7PLICATA, Id. Ibid., pi. xxii, fig. 2, 1839. 



— TEANSVEBSALis, M'Coy. Sil. Foss. Ireland, p. 28, 1846. 



— — Bav. Lond. Geol. Journ., vol. i, p. 57, pi. xii, figs. 17 — 19, 



1847; and Bull. Soc. G^ol. France, ser. 2, vol. v, p. 318, 

 pi. iii, fig. 10, 1848. 



— DuvALii, Dav. Lond. Geol. Journ., vol. i, p. 58, pi. xii, figs. 



20 and 21, 1847. 

 — • TRANSVERSALIS, Phillips and Salter. Mem. Geol. Surv., vol. ii, p. 286, 



1848. 



— — Barrande, Brach. Bohmen ; Natur. Abhandl., vol. ii, 



p. 73, pi. xxi, figs. 19 and 20, 1848. 

 Obthis — Quenstedt. Handbuch, p. 488, pi. xxxix, fig. 18, 1851. 



Lept^Na — Rail. Pal. New York, vol. ii, p. 256, 1852. 



— — M'Coy. Brit. Pal. Fobs., p. 240, 1852. 



