SPIRIFERIDtE. 



95 



Position and Locality. Spirifera sulcata occurs in the Wenlock Limestone at Dudley, 

 Benthal Edge, Wenlock Edge, Lincoln Hill, and Hay Head, near Walsall ; also in the 

 Wenlock Shale, and the Wenlock Limestone of May Hill, Malvern, and Woolhope 

 (Salter). It is not rare in rocks of a similar age in the Island of Gothland.^ 



Spirifera elevata, Dalman. PI, X, figs. 7— II. 



Delthyris elevata, Dalman. Vet. Acad. Handlingar, f. 1827, p. 120, tab. iii, fig. 3, 

 1828. 



— — Sisinger. Lethsea Suecica, p. 73, tab. xxi, figs. 3, a, b, 1837. 



Spirifek octoplicatus. Sow. Silurian System, pi. xii, fig. 7, 1839 (not Sp. octo- 

 plieatus. Sow., Min. Conch., tab. 562, 1827).'; 



— PTYCHODES, Sow. (not of Dalman). Sil. Syst., tab. iii, fig, 13, 1839. 



? — SPURIUS {Barrande), Davidson and De Verneuil. Bull, Soc. Geol. France, 



2nd ser., vol v, pp. 324 and 347, pi. iii, fig. 40, 1848. 

 Spirifera ptychodes, Phillips and Salter. Mem. Geol. Survey, vol. ii, part 1, p. 293, 



1848 (not Hisinger). 

 Spirifee subspurius, D'Orhigny. Prodrome, vol. i, p. 42, 1849. 



— elevatus, Idem. Ibid. 



— — Morris. Catal. Brit. Foss., p. 151, 1854, 



— — Salter. Siluria, 2nd ed., pi. xxi, figs, 5, 6, 1859. 

 Spirifera subspuria, M'Coij. Brit. Pal. Foss,, p. 195, 1852. 



Spec. Char. Transversely rhomboidal; hinge-line nearly or quite as long as the 

 width of the shell; cardinal angles either angular or slightly rounded. Dorsal valve 

 less convex than the opposite one, vrith from eight to twelve simple ribs, which 

 are divided by a mesial fold, equalling in width the adjoining two ribs, moderately 

 elevated, and grooved along the middle. Ventral valve much arched and gibbous ; beak 

 incurved ; mesial sinus as wide as is the fold in the opposite valve, and margined by a 

 strong rounded rib or ridge on each side ; from four to six ribs on either side of sinus. 

 Surface of both valves regularly crossed by numerous slightly projecting lines, as well as 

 by delicate longitudinal and transverse strise. Area triangular, moderately broad, fissure 

 partly closed by a deltidium in two pieces. Specimens vary much in size ; two measured — 

 Length 9, width 1 2, depth 8 lines. 

 „ 7, „ 9, „ 6 „ 



Ohs. This shell is one of the most common in our Upper Silurian rocks. It varies 



' I may here mention that, having received from my friend Lindstrom, of Wisby, a complete series of 

 all the species of Silurian Brachiopoda hitherto discovered in Gothland, I have been able to carefully 

 compare our British shells with those found in Sweden ; and the student will be glad to know that 

 Herr Lindstrom has sent a similar collection to the British Museum, which of course may be readily 

 consulted there. 



