512 EET. 0. E. WHIDBOENE ON SOME EOSSILS 



convex and less oblique shell. Its lower margin forms a semicircle, 

 curving more strongly at each extremity. Compared with L. glabra, 

 Miinst., Goldf. Petr. G-erm. 1. 102. fig. 9, it is much shorter and less 

 trigonal. 



Lima semicieculaeis, Goldf. 



1833. Lima semicircularis, Goldf. Petr. Germ. t. 101. fig. 6. 

 1853. L. semicircularis, Chapuis & Dew. Foss. de Lux. t. 30. fig. 5. 



1857. Lima semicircularis, Oppel, Jura, p. 415. 



1858. Plagiostoma semicirculare, Querist. Jura, t. 59. fig. 11. 

 There are specimens of this shell from the ParJcinsoni-zone of 



Kodborough at Jermyn Street, and from the Ru7njj7iriesianus-zoiie 

 of Dundry in the Bristol Museum ; and I have obtained it from the 

 ParJcinsoni-zone of Bradford Abbas. The fine valve from Eodborough 

 measures 2 j inches long, by 3| wide, and f deep. The specimens 

 seem to agree exactly with the German shell, and to differ from 

 L.notata, Goldf., by their much finer radiations. 



The shell figured under this name by Morris and Lycett in their 

 Monograph (pt. 2, t. 3. fig. 3), of which the types are also at Jermyn 

 Street, does not belong to the same species. It has much larger 

 and fewer ribs, and a more diffuse posterior ear, and appears to 

 be the same as Lima virdunensis, of Buvignier, Statist. Geol. de 

 la Meuse, t. 18. fig. 30. I am not aware that it is even found in the 

 Inferior Oolite. 



Lima semesrjda, n. sp. Plate XVII. figs. 11, 11a. 



Shell transversely convex, very attenuated in front, dilated in 

 the postero -inferior region, flattened posteriorly. Umbo incurved, 

 acute, distant, facing forwards. Anterior wing small, hardly pro- 

 jecting beyond the lunule ; posterior wing rather large and con- 

 fluent, Lunule large, scarcely concave. Lima-line almost the same 

 length as the shell. Surface smooth, except the lunule and the 

 part over the lima-line, which are covered by nine raised distant 

 ridges with smooth interspaces. 



Dimensions. Length 17 lines, width 11 lines, depth of one valve 

 3 lines. 



There is one specimen of this shell from Nailsworth in the 

 Jermyn-Street Museum. 



This species is very distinct both in its shape and in the sudden 

 cessation of its decoration. The surface is very much arched over the 

 whole length of lima-line, and thence spreads out almost flatly to 

 the lower and hind margins. 



Lima Shaepii, n. sp. Plate XVII. figs. 12, 12 a. 



Shell flatly ovoid. Lima-line short. Umbo sharp and small. 

 Ears not compressed, well developed, and equal. Anterior ear 

 rugged, spreading well out beyond lima-line. Surface dilate behind. 

 Bibs about 40, distinct over all the surface, with low and rather 

 flattened tops, distant, simple, and somewhat undulating, with 

 shallow, smooth, flat furrows, which are decidedly wider than the 



