EEOM THE EXFEEIOE OOLITE. 489 



1849. T. Orbicjnyi, D'Orb. Pal. Fr. Amm. Jur. t. 231, & t. 232, 

 figs. 1 & 2. • 



1881. T. Orbignyi, Buckm. Q. J. G. S. vol. xxxvii. p. 608. 



Mr. Buckman records its occurrence in the Inferior Oolite of Half- 

 way House, and the specimen from which the accompanyiug figure 

 is taken came from the same locality. 



Osteea coxcexteica, Miinst., var. mttxda. Plate XV. fig. 1. 



1834. ? Ostrea concentrica, Miinst, Goldf. Petr. Germ. t. 80. fig. 1 

 (only?). 



1836. ? 0. lingua, Rom., Verst. ool. Geb. t. 3. fig. 6 (also figs. 7 

 &12). 



1837. ? 0. multiformis, Koch & Dunker, Verst. nordd. Ool. t. 5. 

 fig. 11 (part). 



1850. ? 0. multiformis, D'Orb. Prodr. pt. 2, p. 54. 



1853.? 0. Sowerbyi, Morr. & Lye. Gt.Ool. Moll. pt. 2, t. 1. fig. 3. 



1861. ? 0. multiformis, Thurm. & Et. Leth. Bruntr. t. 39. fig. 5. 



1864. ? 0. multiformis, Seeb. Hann. Jur. p. 94. 



1871.? 0. Sowerbyi, Phill. 'Valley of the Thames,' t. 4. fig. 3. 



1871.? 0. Sowerbyi, Terq. & Jour. Mem. Soc. Geol Prance, ser. 

 2, vol. ix. pp. 133, 134. 



? 1871. 0. concentrica, Terq. & Jour. Mem. Soc. Geol. France, 

 ser. 2, vol. ix. pp. 133, 134. 



Shell nearly flat, equilateral, very long and narrow, egg-shaped, 

 but more pointed at umbo, which represents the small end of the egg. 

 Umbo central, acute and distinct, but very small. Margins in a 

 very continuous and similar curve on both sides. Bight valve nearly 

 flat and slightly smaller than the other, which is rather more convex, 

 and has coarse, irregular, and sometimes slightly nodulous growth- 

 lines crossing the shell in low curves, so as to be lost in the sides, 

 and not symmetrical with the marginal curve. 



Dimensions. An unusually large specimen measures 2| inches in 

 length. 



Three specimens in the Jermyn-Street Museum from Sudely Hill 

 and the ParJcinsoni-zone of Cheltenham. These specimens are of a 

 neat and regular form, and appear very like Goldf uss's species, to 

 which, I suppose, they belong, but are rather longer, and would 

 appear to have a smaller hinge. A much larger but similarly 

 shaped shell in the British Museum, comes from the Inferior Oolite of 

 Glastonbury. Small oysters are frequent at Dundry, which are 

 coarse and irregular in shape ; but it may be that these belong to 

 the same species. If so it would be a very variable shell, and 

 correspond with 0. lingua, 0. multiformis, &c. of the higher Jura, 0. 

 Sowerbyi possibly being an extreme variety. 



The Jermyn-Street fossils have two or three longitudinal, parallel, 

 rugose marks on the right valve, not centering in the umbo, but 

 probably taken from some substance of attachment, after the manner, 

 as Mr. Newton pointed out, of Ostrea irregularis, Miinst. 



Whether Terquem's shell is the same may be doubtful, as he 

 states it to be a thin and slightly rayed shell, which does not ap- 

 pear from Goldfuss's figure or description. 



2n 2 



