ADDITIONS. 423 



ADDITIONS AND CORRECTIONS. 



Akca, sp. [Vol. I, p. 35.] 



Internal casts of a species of Area have been found in the zone of Belemnitella 



mucronata of Norwich. Two examples are preserved in the Norwich Museum (Nos. 

 2121, 2122). 



DlCRANODONTA. [Vol. I, p. 53.] 



Species of Dicranodonta have now been recognised by Borissjak 1 in the Jurassic 

 deposits of Russia. In connection with this genus or subgenus the papers of 

 Solger ~ and Schmidt 3 should be consulted. 



Crenella orbicularis (Soiverby), 1886. Plate LXL figs. 14—17. 



[Omitted from Vol. I, p. 105.] 



1836. Lctcina ? orbicularis, J. de C. Sowerby. Trans. Geol. Soc, ser. 2, vol. iv, 



pp.241, 341, pi. xvi, fig. 13. 

 1850. Lucina orbicularis, A. d'Orbigny. Prodr. de Pal., vol. ii, p. 162 (partim). 

 1854. — J. Morris. Cat. Brit. Foss., ed. 2, p. 208. 



1866. — F. J. Pidet and G. Campiche. Foss. Terr. Cre't. Ste. 



Croix (Mater. Pal. Suisse, 

 ser. 5), p. 291. 

 1871. Lucina? orbicularis, F. Stoliczlca. Palseont.Indica, Cret. Fauna S. India, 



vol. iii, p. 252. 



Description. — Shell thin, small, oval, higher than long, slightly inequilateral, 

 regularly convex, with rounded margins. Umbones pointed, with a small anterior 

 curvature. Lunule and escutcheon not denned. Ornamentation consists of numerous, 

 equal, regular, radial ribs which curve outwards from the median line of the valve 

 and are separated by narrow furrows. A few growth-rings occur at intervals. 



1 " Pelecypoden Jura-ablager. Europaeisch. Eussland. II Arcidae," 'Mem. Com. geol.,' n.s., xix 

 (1905), pp. 29—32, 58-60, pi. iv, figs. 5—13. 



2 " Ueber Pseudocucullsea, einen neuen Taxodontentypus," ' Zeitsclir. d. deutscli. geol. Gesellscli.,' 

 vol. Iv (1903), Monatsber., p. 76. 



3 Ibid., vol. lvi(1904), Monatsber., p. 120. 



