SHELLS OF THE WENLOCK LIMESTONE. 



625 



crossed by imbricating scales, especially near the edge ; front much elevated. Length 8 lines ; 

 width the same. 



If specimens we have seen from Sweden be correctly labelled, T. marginalis of Dalman is 

 probably the same species. 

 Loc. WenlocTc Edge. 



Terebratula cuneata, f. 13. {Balm. I. c. p. 141. t. vi. f. 3. His. Pet. Suec. p. 81. t. xxiii. f. 5.) Tri- 

 angular, longer than wide, depressed, strongly plaited; plaits 10 or 12, straight, of which a few 

 in the front are elevated ; beak of the larger valve straight, produced. Length I inch ; width 

 5 lines ; depth of each valve 2 lines. 



Peculiar to the Wenlock Limestone. 

 Loc. Wenlock and Lincoln Hill ; Budley ; Abberley. 



Terebratula bidentata, f. 13 a. {Balm. I. c. p. 142. t. vi. f. 5. His. Act. Holm. 1826. t. vii. f. 5. Pet. 

 Suec. p. 81. t. xxiii. f. 7.) Triangular, with a rounded front, smooth, depressed, strongly plaited ; 

 plaits acute, about 8, two of which in the front are raised ; beak sharp. Length 3 lines ; width 

 3 1 lines. 



Much like the last, but shorter and furnished with fewer plaits. 

 Loc. Budley ; Abberley. 



Terebratula deflexa, f. 14. Transversely obovate, gibbose, sharply plaited; plaits about 24, of which 

 4 or 5 in the front are turned downwards ; beaks small, adpressed. Length nearly 5 lines ; 

 width 6 lines \ depth 4£ lines. 



A rare species, remarkable for the sinus in the front being in the larger or lower valve. 

 Loc. Wenlock Edge. 



Terebratula Wilsoni; (See PI. 6. f. 7-) common at Aymestry ; rare in the Wenlock formation. 

 Loc. Limestone Quarries, Eastnor Park. 



Terebratula Nucula? ; (See PI. 5. f. 20.) ; also Ludlow Rock. 



If this differ at all from the Ludlow species, it is in being rather flatter. 

 Loc. Limestone Quarries, Eastnor Park ; Budley ; and Western slopes of the Malvern Hills. 



Patella? implicata, f. 14 a. Oval, depressed, surface composed of concentric laminae. Longest di- 

 ameter 2 lines. 



We have only seen the upper surface of this small shell, and therefore assign its generic name 

 with doubt; it bears some resemblance to P. antiquissima, {His. Pet. Suec. p. 45. t. xii. f. 10.) 

 and may represent that fossil in its young state. We have several individuals all of one size, 

 on the same mass of stone with Spirifer octoplicatus ?. 

 Loc. Abberley. 



Nerita spirata, var.? f. 15. {M. C. t. 463. f. 1, 2.) Subglobose, smooth; spire small; upper part of 

 the whorls flattened ; aperture transversely oval. Height f inch; diameter the same. 



This has a slightly more prominent spire than Nerita spirata, M. C, and the upper part of 

 the whorls are less flattened and smoother; but as the species of the Carboniferous Limestone 

 also varies in these points, we do not feel justified in considering this distinct. 

 Loc. Nash Limestone ; Presteign; Ledbury; New's Wood, Eastnor Park. 



Nerita Haliotis, f. 16. Subglobose, with the last whorl greatly expanded towards the aperture, and 

 irregularly undulated; spire small, rather sunk; aperture orbicular. Height 1 inch ; diameter 

 1 inch 4 lines. 



Some specimens are so flat as to resemble a Haliotis or Sigaretus, and many have a furrow 

 around the upper part of the last whorl. 



Loc. Ledbury, and West flank of Malverns ; Wren's Nest, §c. 3 Budley. 



