10 



CRETACEOUS LAMELLIBRANCHIA, 



Sub-genus — Plagiostoma, J. Sowerby, 1814. 



('Min. Conch.,' vol. i, p. 175.) 



Lima (Plagiostoma) subrigida, Bomer, 1836. Plate III, figs. ha, b, 6—9. Text- 

 figs. 1, 2, 3. 



183G. Lima subrigida, F. A. Bomer. Verstein. nord-deutsch. Oolithen-geb., p. 79, 



pi. xiii, fig. 16. 

 plana, Bomer. Ibid., p. 80, pi. xiii, fig. 18. 



— subrigida, Bomer. Die Verstein. d. nord-deutsch. Kreidegeb., p. 57. 



— plana, Bomer. Ibid., p. 57. 

 subrigida, G. Bohm. Zeitschr. d. deutsch. geol. Gesellsch., vol. xxix, 



p. 235. 

 — A. Wollemann. Ibid., vol. xlviii, p. 836. 



Wollemann. Die Biv. u. Gastrop. d. deutsch. u. holliind. 

 Neocoms (Abhandl. d. k. preussich. geol. 

 Land., N.P., pt. 31), p. 30. 



1841 



1877 



1896 

 1900 



Fio. 1. — Lima (Plagiostoma) suhrigida,Ji6mer. Claxby Ironstone, Lincolnshire. Eight valve. Natural size. 

 Sedgwick Museum, Cambridge. 



Description, — Shell convex, oval, height slightly greater than length ; antero- 

 dorsal margin nearly straight, postero-dorsal much shorter and nearly straight, the 

 remainder rounded and forming a regular curve. Apical angle rather more than a 



