80 CRETACEOUS LAMELLIBRAKCHIA. 



Tkigonia DvEDALea, FarJdiisoa, 1811. 



Additional Synonymy. 



1828. Trigonia d^t^dalea, Drfrancc. Diet. Sciences uat,, vol. Iv, p. 294. 



1868. — — A. Briart and F. L. Cornet. Descript. Mincralog. 



Gcol. et Pal. do la Meule de Bracquegnios (Mem. 



cour. et Mem. des Sav. etraugers, vol. xxxiv), 



p. 64', pi. vi, figs, 1 — 3. 

 1875. — — Lyceit, p. 100, pi. xxii, figs. 7, 8; pi. xxiii, figs. 2, 3; 



1)1. xxviii, fig. 8. 

 1875. — — var. confusa, Lycett, p. 102, pi. xxiii, fig. 1. 



Nou 1819. — u.KDALEA, Lamarck. Auim. saus Vert., vol. vi, p. 63 (ed. 2, 



1836, p. 516), from LeMans. 

 — 1866. — —F.J. Pictet and G. Campiclie. Foss. Terr. Crct. Ste. 



Croix (Mater. Pal. Suisse, ser. 4), p. 371. 



Bemarh. — Lycett regarded T. i^almata, Desliayes,^ as a variety of T. dsedalea ; 

 but it should be noted that the former occurs at a distinctly lower horizon than the 

 latter, namely, in the Middle Neocomian of the Aube. I have seen no example of 

 T. jxdmata. 



Types. — I have not found the type. The specimens figured by Sowerby are in 

 the British Museum; those figured by Lycett are in the Museum of Practical 

 Geology, except the type of the variety confusa, which is in Mr. Vicary's collection. 

 The type of T. quadrata, Sowerby, is in the Bristol Museum. 



Distribution. — Greensand of Blackdown (Zone xii) and Haldon. 



Trigonia spectabilis, Sowerhi/, 1826. 



1875. Lycdf, p. 112, pi. xxxvi, figs. 1 — 4. 



Remarks. — I do not think that Lycett's view of the identity of the species figured 

 by Pictet and Roux^ as T. nodosa with T. spectabilis can be maintained. In the 

 former the area is smaller, the posterior extremity more produced and rounded, the 

 tubercles smaller and more rounded and not forming such distinct rows as in T. 

 spectabilis. 



1 ' Mem. Soc. gcol. France,' vol. v (1842), p. 7, pi. viii, fig. 5. 



-' ' Moll. Foss. Gres verts de Geneve ' (1852), p. 454, pi. xxxv, tig. 5. 



