504 EEV. G. F. WHIDBOENE ON SOME EOSS1LS 



and regularly convex ; the posterior side much more convex ; but 

 the curves are very even ones, without sudden changes of curvature. 

 Surface with about fifty high, narrow, acute and distant ribs, with 

 rounded tops and perpendicular sides, cut by three or four sharp 

 growth-lines near the margin, and separated by flat broad furrows 

 three or four times the width of the ribs, which are crossed by very 

 distinct and numerous, long, ladder-like striae, convex towards the 

 umbo. 



One specimen in the Jermyn-Street Museum, from Broadwindsor. 



Dimensions. About 3 inches long, by 2| wide, and 1 deep (for 

 both valves). 



It approaches Lima Renevieri, Etallon, Leth. Bruntr. t. 34. f. 4, 

 but is a much less convex shell, and differs from both that shell and 

 from L. notata, Miinst., by the extremely narrow and perpendicular 

 ribs with which it is covered. 



Lima alticosta, Chap. & Dew. 



1853. Lima alticosta, Chapuis & Dewalque, Eoss. Terr. Sec. Lux. 

 t. 28. fig. 3. • 



1858. ' Plagiostoma sulcatum gingense, Quenst. Jura, t. 51. fig. 2. 



1867. Lima alticosta, Waagen, in Benecke's geogn.-pal. Beitr. 

 p. 625. 



There are specimens of this shell in the Bristol Museum, from the 

 upper part of the Humphriesianus-zone of Dundry (from which place 

 I have myself obtained it), and in the Jermyn-Street Museum, from 

 Yeovil and Rodborough. 



It differs from Lima pontonis, Lycett, Quart. Journ. Geol. Soc. 

 vol. x. t. 14. fig. 2, in being much less transverse. 



Lima amnifeea, n. sp. Plate XVII. fig. 2. 



Shell very flat, oblique, ovoid, transverse. Umbones small, acute, 

 elevated, and very slightly incurved. Lima-line short and low. 

 Ears small, dilate, receding, and nearly equal. Lunule small and 

 slightly concave. Antero -inferior margin roundly convex, the 

 marginal curve gradually decreasing towards the posterior border, 

 which becomes somewhat concave in forming the ear. Surface 

 moderately convex behind the lima-line, and flattening out from the 

 centre to the other edges, which meet at a very small angle ; covered 

 with frequent but irregular concentric growth-lines, and radiated 

 by very numerous (seventy) slightly undulating, impressed lines of 

 very coarse and distant puncta, which vanish towards the central 

 portions of the shell. 



Dimensions. 22 lines long, by 17 wide, and 6 lines deep for the 

 closed valves. 



This species occurs abundantly in the beds of the Jurensis-zone 

 below the sands at Yeovil Junction, and sometimes gives indications 

 of concentric colour-bands. There are three specimens from that 

 place in the Jermyn-Street Museum. 



It is very similar to Lima aciculata, Miinst., but differs in the size 

 and shape of its posterior wing, in its less orbicular form, and in 



