84 LAMELLrBRANCHIATA. 



Orthonota nasuta (Conrad), F. McCoy, Brit. PaliEOz. Foss. (1852), 

 pi. i I, f. 23, p. 275. Middle Bala; Horderley West. 



O. semisulcata (Sowerby), F. McCoy, Brit. Palseoz. Foss. (1852), 

 pi. i K, f. 25, p. 275. Upper Ludlow ; Kirkhy Moor, Kendal. 



O. truncata (McCoy). Leptodomus truncatii^, F. McCoy, A. M. 

 N. H. ser. 2, vii (1851), p. 57, and Contrib. Brit. Pal. (1854), 

 p. 192, and Brit. Pal^oz. Foss. (1852), pi. i K, f. 21—24, p. 279. 

 Upper Ludlow ; Benson Knot, Kendal. 



Ostrea acutirostris, Nilsson, R. Etheridge, Appendix to W. H. 

 Penning and A. J. Jukes-Browne, Geol. Cambridge (1881), 

 pi. iii, f. 5, 6, p. 146. Lower Chalk (Tottemhoe Stogie); Btirwell. 



O. (Exogyra) couloni (Defrance), W. Keeping, Foss. Upware 

 and Brickhill (1883), p. 100. Lmuer Greensand ; Upware. 



O. curviroBtris, Nilsson, var. inflexa, R. Etheridge, Appendix 

 to W. H. Penning and A. J. Jukes-Browne, Geol. Cambridge, 

 (1881), pi. iii, f. 7, 8, p. 146. Lower Chalk (Tottemhoe Stone) ; 

 Burwell. 



O. (Gryphea) dilatata?, Sowerby, W. Keeping, Foss. Upware 

 and Brickhill (1883), p. 102. Lower Oreensand; Upware. 



O. frons, Parkinson, var. macroptera, Sowerby, W. Keeping, 

 Foss. Upware and Brickhill (1883), p. 102. Lmuer Greensand; 

 Uptvare. 



O. knorri, Voltz, G. F. Whidborne, Q. J. G. S. xxxix (1883), 

 pi. XV, f. 2, 3, 3 a, p. 490. Fig. 2, Inferior Oolite ; Bradford 

 Ahhas. Fig. 3, Fidler's Earth; Frame. Presented by the 

 Rev. G. F."^ Whidborne, M.A. 



O. lagena, H. G. Seeley, A. M. N. H. ser. 3, vii (1861), pi. v, f. 2, 

 p. 117. Cambridge Greensand; Cambridge. 



O. (Exogyra) lingulata [Walton MS.], J. Lycett, Supp. Mon. 

 Moll. Gt. Ool. etc. (1863), pi. xxxii, f. 2, 2 a, b, p. 108. Forest 

 Marble ; Farleigh and Pound Hill. Walton Collection. 



O. marshi, Sowerby, J. Morris and J. Lycett, Mollusca Gt. Ool. 

 part ii (1853), pi. xiv, f. 2, p. 126. Lnfenor Oolite {Grey 

 Limestone) ; Gristhorpe Bay, near Scarborough. 



Another specimen, young individual, Morris and Lycett, 



