ATRYPA. 51 



Cyrtina ? Amblygona, Phillips (sp.). PI. IX, figs. 18 — 20. 



Terebratula Amblygona, Phillips. Palaeozoic Fossils of Cornwall, Devon, and West 



Somerset, p. 88, pi. xxxv, fig. 160, 1841. 



Spec. Char. Shell oblong, somewhat pentahedral, nearly as wide as long ; hinge-line 

 rather shorter than the width of the shell ; dorsal valve slightly convex ; mesial fold rather 

 flat, of small elevation, originally with one narrow rib, but gradually widening and forming 

 two additional ribs by bifurcation, or by the juxtaposition of a lateral rib ; eight or ten 

 other simple ribs ornament the surface of the valve ; ventral valve convex, deeper than 

 the opposite one ; sinus shallow, rather fiat, and composed of two ribs at its origin, but 

 these bifurcate at a short distance from the extremity of the beak ; the area is triangular, 

 rather large; fissure narrow, arched over by a pseudo-deltidiura. Two specimens have 

 measured : 



Length 7, width 6, depth 3 lines. 



Obs. Having procured from Mr. Lee the loan of the figured type, and removed the 

 matrix which obscured the beak and a portion of the surface of the dorsal valve, I soon 

 perceived that the shell belonged either to Spirifera or Cyrtina, and not to Terebratula, 

 as had been supposed by Phillips. Not having been able to examine its interior arrange- 

 ments, I am uncertain whether it should be classed under Spirifera or Cyrtina, and have 

 therefore left it provisionally with the last-named sub-genus. Two specimens were found 

 by Mr. Lee in the Middle Devonian Limestone of Barton, and I have another from Lum- 

 maton, near Torquay. 



Genus — Atrypa, Dalman, vel Spirigerina, D 'Orbij/ny. 

 Atrypa lens, Phillips (sp.). PL X, fig. 1. 



Orthis lens, Phillips. Palaeozoic Fossils of Cornwall, Devon, and West Somerset, p. 65, 



pi. xxvi, fig. 110"-*, 1841. 

 Terebratula dividua, Schnur. Programm der vereinigten hobern burger und provinzial 

 Gewerbeschule zu Trier, p. 6, 1851, and in Dunker und Von Meyer's 

 Palseontographica, vol. iii, p. 179, pi. xxiv, fig. 2, 1853. 

 Orthis lens, UArchiac and Be Verneuil. Description of the Older Deposits of the 

 Rhenish Provinces, Trans. Geol. Soc, 2d series, vol. vi, p. 396. 

 — — Morris. Catalogue of British Fossils, p. 140, 1854. 



Orthis Eifliensis, J. Steininger. Geognostische Beschreibung der Eifel, p. 80, pi. v, 

 fig. 5, 1853. 



Spec. Char. Shell small, compressed, longitudinally oval, notched in front ; valves 

 almost equally deep, very slightly convex, with a longitudinal sulcus or groove along the 

 centre of each valve, but usually deeper in the dorsal one ; surface ornamented with from 



