84 LAMELLTBRANCHIATA. 



Orthonota nasuta (Conrad), F. McCoy, Brit. Palaeoz. 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 ; KirTcby Moor, Kendal. 



O. truncata (McCoy). Leptodomus truncatus, F. McCoy, A. M. 

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

 p. 192, and Brit. Palseoz. Foss. (1852), pi. i K, f. 2124, 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 (Totternhoe Stone); BurwelL 



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

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



O. curvirostris, 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 (Totternhoe Stone) ; 

 BurwelL 



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

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



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

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

 Upware. 



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 

 Abbas. Fig. 3, Fuller's Earth; Frome. Presented by the 

 Rev. G. F/ Whidborne, M.A. 



O. lagena, H. G. Seeley, A. M. N. H. ser. 3, vn (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. Inferior Oolite (Grey 

 Limestone) ; Gristhorpe Bay, near Scarborough. 



Another specimen, young individual, Morris and Lycett, 



