84 LAMELLIBRANCHIATA. 
Orthonota nasuta (Conrad), F. McCoy, Brit. Palseoz. Foss. (1852), 
pl. it, f. 28, p. 275. Middle Bala; Horderley West. 
O. semisulcata (Sowerby), F. McCoy, Brit. Palzeoz. Foss. (1852), 
pl. ik, f. 25, p. 275. Upper Ludlow ; Kirkby Moor, Kendal. 
O. truncata (McUoy). Leptodomus truncatus, F. McCoy, A. M. 
N. H. ser. 2, vit (1851), p. 57, and Contrib. Brit. Pal. (1854), 
p- 192, and Brit. Palseoz. Foss. (1852), pl. 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), 
pl. i, 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), pl. i, £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. xxx1x (1883), 
pl. xv, f. 2, 3,3 a, p. 490. Fig. 2, Inferior Oolite ; Bradford 
Abbas. Fig. 3, Fuller's EHarth; Frome. Presented by the 
Rev. G. F. Whidborne, M.A. 
O. lagena, H. G. Seeley, A. M. N. H. ser. 3, vit (1861), pl. v, f. 2, 
p. 117. Cambridge Greensand ; Cambridge. 
O. (Exogyra) lingulata [Walton MS.], J. Lycett, Supp. Mon. 
Moll. Gt. Ool. ete. (1863), pl. 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 11 (1853), pl. xiv, f. 2, p. 126. Inferior Oolite (Grey 
Limestone) ; Gristhorpe Bay, near Scarborough. 
Another specimen, young individual, Morris and Lycett, 
