130 



BRITISH SILURIAN BRACHIOPODA. 



Terebrattjla affinis, Sowerby. Min. Con., vol. iv, p. 324, fig. 2, Jan., 1822. 

 Atrypa reticulaeis, Dal. Vet. Akad. Verhandl., p. 127, pi. iv, fig. 2, 182/. 



— ASPERA, Id. Vet. Ak. Handl., p. 128, pi. iv, fig. 3, 1827. 

 Terebratula aspeea, Def. Diet. vol. liii, p. 164, 1828. 



— cancellata, Eichw. Zoologia Specialis, vol. i, p. 276, pi. iv, fig. 11, 1829. 

 PORAMBONiTES MAXIMA, Pander. Beitrage zur Geol. Russl., p. 16 B, fig. 7, 1830. 

 Atrypa RETICULAEIS, var. ALATA, Hisviger. Bidrag till Sveriges Geognosi, part v, 



p. 120, pi. iii, fig. 4, 1831. 

 Teeebratula prisca. Von Buck. Ueber Terebr., p. 71, 1834. 



— RETICULARIS, Bronn. Leth. Geog., p. 72, pi. ii, fig. 10, 1837. 

 Atrypa reticularis. His. Lethaea Suecica, p. 75 ; and var. /3 alata, ibid., pi. xxi, 



figs. 11 a—e, 1837. 

 Terebratula prisca, Pusch. Polens Palaeont., p. 26, 1838. 



— — Von Buck. Mem. Soc. Geol. France, vol. iii, pi. xvi, fig. 19, 1838. 

 Atrypa affinis, Sow. Sil. Syst., pi. vi, fig. 5, 1839. 



— ASPERA, Id. lb., pi. xii, fig. ,5. 



— orbicularis, Id. lb., pi. xix, fig. 3. 



Terebratula prisca, Von Buck. Beitrage zur Geog. Russl. 17, 58, 66, 1840. 



— ARMiGERA, Id. Von Buch, Beitrage zur Geol. Russ., p. 108, 1840. 

 Atrypa prisca, Phillips. Palaeoz. Foss., p. 33, fig. 135, 1841. 



Terebratula reticularis, Murch. Vern. and Keys. Russia and Ural, p. 91, pi. x, 

 fig. 12, 1845. 



— — Barrande. Sil. Brach. Bbhmen, p. 95, tab. xix, figs. 



8, 9, 1847. 



Atrypa — Hall. Palaeont. New York, vol. ii, pp. 72 and 270, 



pi. xxiii, 1851. 



— — S.P.Woodward. Manual of the Mollusca, p. 228, 1854. 

 Terebratula prisca, Eichw. Sil. Syst. in Ehstl., p. 141, 1858. 



Ateypa eeticularis, Salter. Siluria, 2nd ed., pi. xxi, figs. 12, 13, 1859. 

 Spirigerina — Lindstrdm. Gottlands Brachiop., p. 362, 1860. 



Ateypa — Dav. Monogr. Brit. Dev. Brach., p. 53, pi. x, figs. 3, 4, 



1864 [as well as in the English, French, and German 

 editions of the General Introduction]. 

 [Many more references might be added, but those given comprise the most important 

 Silurian names ; and to extend the list would be unnecessary : for Devonian synonyms, 

 see p. 53 of my Devonian Monograph.] 



Spec. Char. Shell obloug-ovate, or transverse ; widest near the hinge ; beak small, 

 acute, very little produced, and generally pressed to the urabone of the dorsal valve, so 

 that the small circular foramen situated under its incurved extremity is rarely percep- 

 tible. Dorsal valve uniformly convex and gibbous, especially so at the umbone and along 

 the middle, sloping gradually to the margin ; hinge-line extended into compressed ears, 

 with or without any defined fold. Ventral valve very slightly convex posteriorly, or from 

 the extremity of the beak to about the middle of the valve, whence it becomes gradually 

 and slightly concave towards the lateral portions of the valve, with sometimes a deepish 

 sinus near the front ; sides of shell rounded, frontal marginal line more or less raised into 



