JURASSIC AND TRTASSIC BRACHIOPODA. 201 



Geological Position. — Rh. Amalthei was found by the Rev. F. Smithe in the top bed 

 of the Am. margaritatus Zone (Middle) Lias at Churchdown in Gloucestershire, also in the 

 Am. communis Zone (Upper Lias) at Churchdown Hill. M. E. Deslongcharaps, having 

 examined the Rev. F. Smithe's specimens, writes to that gentleman that the species occurs 

 in great abundance in Normandy in the Zones of Am. margaritatus and Am. spinatus ; 

 and that it is remarkable on account of its small size and characters, which partake 

 of those of Rh. tetraedra and Rh. rimosa, with the young ages of which it has been 

 often confounded. Mr. J. F. Walker has met with the shell at South Petherton ; 

 Mr. Walford obtained it from the Am. spinatus Zone at Thenford, near Banbury. In 

 Germany it occurs in the Margaritatus-zom at Heiningen, Zell, Ohmenhausen, Balingen, 

 and Breitenbach. 



190. Rhynchonella sub-decorata, Dav. Ool. Mon., PI. XVIII, fig. 10, and Appendix 



to vol. i, p. 21, PI. A, figs. 23—26. 



Nothing new. Inferior Oolite, Cheltenham district. 



191. ? Rhynchonella quadriplicata, Zieten. Dav., Appendix to vol. i, p. 23, PI. A, 



fig. 22 ; Sup., PL XXIX, figs. 1, 2, 3. 



Rhynchonella quadriplicata, Zieten. Die Verst. Wurtemb., pi. xli, fig. 3, 1832. 



— — Desl. Bull. Soc. Linn, de Normandie, vol. ii, p. 54, 



pi. v, 1857. 



Shell subpentagonal, slightly wider than long. Dorsal valve divided into three lobes, 

 of which the central one forms a large projecting mesial fold, and corresponds with a 

 wide, shallow sinus in the opposite one. Beak much incurved. Surface ornamented 

 with eighteen strong, radiating ribs, of which four usually occupy the fold, while a small 

 and slightly marked additional one is situated on each of the lateral outward slopes of 

 the fold. 



Length 18, width 19, depth 11 lines. 

 Obs. — I am very uncertain with respect to the identification of this shell, which must 

 be considered as provisional. Dr. Wright found the described and figured specimen in 

 the Inferior Oolite at Cleeve Hill, near Cheltenham. It occurs in beds of a similar age 

 at Les Moutiers, Bayeux, and other places in France. Dr. Brauns, in ' Der untere Jura 

 im nordwestlichen Deutschland,' 1871, considers both Rh. quadriplicata and Rh. quinque- 

 plicata of Zieten to be mere varieties or synonyms of R. tetraedra. At p. 315 of his 



26 



