ATRYPA. 53 



angular; foramen minute, a small flattened space existing between the beak-ridges and 

 the hinge-line ; dorsal valve elliptical and flattened, with a wide, shallow, median depres- 

 sion, or sinus, extending from the umbone to the front, while a small longitudinal rib 

 occupies the centre, the sinus being limited on each side by a rounded rib. The surface 

 of each valve is closely and regularly intersected by numerous squamose concentric laminae. 



Length 4, width 4, depth 2 lines. 



Obs. I was glad to recognise a specimen of this interesting little species in the 

 collection of the Rev. J. E. Lee, who had found it in the Middle Devonian Limestone of 

 Barton, near Torquay, where the shell appears to be rare. It does not appear to have 

 attained much larger proportions than those above given. It is stated to be also rather 

 uncommon in the Eifel, from whence, however, I have obtained about a dozen specimens. 

 It has been beautifully figured by M. De Verneuil and Professor Schnur. Viscount 

 D'Archiac and M. De Verneuil have likewise observed that " its form would bring this 

 species into Atrypa of Dalman, if that genus could be preserved in a scientific classification, 

 which they think it cannot." My learned friends were, however, mistaken in this last 

 supposition, for whether the shells in question be termed Atrypa or Spirigerina, the genus 

 is among the best we have in the classification ; and under no circumstance could the shell 

 be considered a Terebratula. Although we have never seen the interior dispositions, I 

 think that the shell must have been provided with spiral appendages similarly disposed 

 to those figured by Schnur in Atrypa lens. 



A. lepida occurs at Priim, Gerolstein, &c, in the Eifel ; and has also been found in the 

 Hartz. 



Atrypa reticularis, Linnaus (sp.). PI. X, figs. 3, 4. 



Anomia reticularis, Idnnceus. Syst. Nat., ed. xii, p. 1132, 1767. 



TEREBRATULA PECTINATE, T. SUBTILISSIME STRIATA, T. CANCELLATjE, T. minutissime 



striata, Schroter. Abhandlungen liber verschiedene Gegenstande der Natur- 

 geschichte, pi. iii, figs. 11 — 18, and pi. iv, figs. 19 — 26, 1777. 

 Terebratula pectinata, Bruguiere. Hist. Nat. Vers. ; Testaces, Encyclopedic Metbodique, 



pi. 242, pi. iv, 1789. 

 Anomites reticularis, Wahlenberg. Nov. Act. Soc. Upsal., vol. viii, figs. 65, 66, 1821. 

 Terebratula affinis, Sowerby. Min. Con., tab. 324, fig. 2, Jan., 1822. 

 Spirifer Sowerbyi, Def. Diet., vol. 1, p. 295, t. Ixxvi, fig. 2 (valva bracbiis spiralibus ornata). 

 Terebratula (Magas) cancellata, Eichw., Zool., i, 276, tab. iv, fig. 11. 

 Terebratulites priscus, Schlotheim. Nachtriigen zur Petrefactenkunde, pi. xvii, fig. 2, 



1822. 

 — explanatus, Schloth. Ibid., pi. xviii, fig. 2. 



Atrypa reticularis, Dalman. Vet. Ac. Handl., pi. iv, fig. 2, 1827 ; Hisinger, Lethaea 



Suecica, pi. xxi, fig. 11. 

 Terebratula prisca, Buck. Ueber Terebrateln, p. 71, 1834. 



