SPIRIFERID^. 



133 



Camp, Shucknall Hill, &c., in the Woolliope district. At Llanbadoc, near Radyr, the 

 Darren, Cefn Ila, &c., in the Usk district, &c. The Rev. J. D. Latouche has found 

 beautiful examples, with the spiral lamellae silicified, in the Aymestry Limestone, near the 

 Craven Arms, in the Ludlow district. It occurs also in the Woolhope Limestone at 

 Littlehope ; in the Upper Llandovery Sandstone of May Hill and Huntley Hill ; at the 

 Hollies Farm, Shropshire ; and in all the Lower Llandovery grits and shales of South Wales 

 it is everywhere abundant, but it is never found lower down in the Caradoc rocks (Salter). 



In Scotland it is common in the Wenlock Shales of the Pentland Hills, and in various 

 localities in the Girvan district, Ayrshire, in Upper and Lower Llandovery rocks. 



In Ireland it occurs at Ferriter's Cove, in beds of Wenlock and Ludlow age ; also at Car- 

 rigonough. County of Wexford, which must, therefore, be a " Llandovery" locality (Salter). 



On the Continent it is a common fossil in Norway, near Christiania ; in Gothland ; 

 in various parts of Russia, as far as the frontier of Siberia ; in Bohemia, and in several 

 other parts of Europe. It has also been found in China, and in very many places in the 

 United States, Canada, Newfoundland, &c. ; and in Devonian times it ranged to AustraHa,and 

 to the extreme northern points reached by Arctic explorers (Salter, 'Brit. Assoc. Reports'). 



Atrypa margin alis, Balman (sp.). Pi. XV, figs. 1, 2. 



Terebratula marginalis, Balman. Kongl. Vet. Akad. Handl., p. 143, pi. vi, fig. 6, 

 1827, &c. 



— — Hisinger. Lethsea Suecica, p. 81, pi. xxiii, fig. 8, a, c, 1837. 



— ^ J. de C. Sow. Sil. Syst., pi. xii, fig. 12, 1839. (T. 



imbricata in the lists.) 



— — Bav. Bull. Soc. Geol. France, 2nd ser., vol. v, p. 331, 1848. 

 Spirigerina — M'Coy. Brit. Pal. Foss., p. 197, 1852. 



— imbricata, Schmidt. Sil. B'orm. Ehstlaud, &c., p. 212, 1858 (but Prof. 



Schmidt refers to Sowerby's figure, pi. sii, fig. 12, which 



is referable to T. marginalis). 

 Ateypa marginalis, Salter. Siluria, 2nd edit., p. 542, pi. xxii, fig. 19 (the upper 



figures only), 1859. 

 Spirigerina — Lindstrdm. Gottlands Brachiop., pp. 362, 363, 1860. 



Spec. Char. Transversely sub-pentagonal, or almost elliptical; hinge-line nearly 

 straight ; lateral margin rounded, very slightly so in front ; beak of ventral valve small, 

 straight, moderately incurved, with a circular foramen under its extremity, and distinctly 

 separated from the umbone or hinge-line of dorsal valve by a deltidium in two pieces, 

 almost entirely surrounding the aperture. Dorsal valve moderately convex and trilobed ; 

 mesial fold extremely narrow at first, and suddenly widening, slightly elevated, flattened 

 along the middle, and sharply separated from the lateral portions of the valve by a 

 deepened groove. The fold is also often abruptly bent upwards close to the frontal edge. 



