SPHENOTUS. 83 



1. Sphenotus Hicksii, n. sp. Plate IX, fig. 9. 



1841. PuLLASTEA ? COMPLANATA, Phillips (not Sowerhy). Pal. Poss., p. 35, 



pi. xvii, fig. 56. 



Description. — Shell rather small, convex, transverse, subquadrate. Hinge- 

 margin with two long, transverse, lateral teeth. Umbo prominent, wide, flattened, 

 incurved, anteriorly truncate, situated at about the anterior third of the length. 

 Anterior margin rather broad, deeply convex. Inferior margin long, straight, or 

 very slightly concave. Postero-inferior corner much produced, roundly convex. 

 Posterior margin probably oblique. Contour of back vertically convex, trans- 

 versely flattened and slightly depressed in the middle ; curving rapidly in front 

 to form an undefined lunule, which is bisected by the produced margins ; bounded 

 behind by a more or less distinct rounded angle or ridge from the umbo to the 

 postero-inferior corner. Posterior slope obliquely flattened. Surface with ten or 

 fifteen irregular undulations, less marked on the sides, and with a minor ornament 

 of minute, crowded, sharpish transverse lines, only seen where the shell is well 

 preserved. Shell-structure thin. 



Size. — Length 25 mm., height 13 mm., depth of valve 5 mm. 



Localities. — In the Museum of Practical Geology is a specimen from the new 

 Ilfracombe Road near Barnstaple; in the Barnstaple Athenaeum, eight from 

 Kingdon's, Shirwell; and in the Porter Collection two from Pilton. 



Remarks.— W\n\e these fossils clearly belong to the species described by 

 Phillips as Pullastra complanata, Sowerby,they are perfectly distinct from Sowerby's 

 own species.^ The latter is a much more oblique and trigonal shell, with a very 

 narrow anterior end, and altogether has a more mytiloid appearance, as seen by 

 his type in the Museum of the Geological Society. 



None of our specimens are very perfect, or give the full shape. The amount 

 of depression in the back and of the transverseness seems to vary considerably. 



One of Mr. Porter's specimens is a cast, and seems to show two long posterior 

 teeth. This is not, however, very clear. 



2. Sphenotus solenoides. Hall.'' Plate IX, figs. 10, 11. 



1870. Sanouinolites solenoides, Hall. Prelim. Notice Laaiell., pt. 2, p. 38. 

 1883. — — Sail. Pal. N. T., vol. v, pt. 1, PJates, pi. Ixv, 



figs. 21—28. 

 1885. Sphenotus solenoides, Hall. Ibid., vol. v, pt. 1, No. 2, p. 398, pi. hv, 



figs. 21—28. 



1 1839, Sowerbj, in Murchison's, * Sil. Sjst.,' p. 609, pi. v, fig. 7. 



