PECTUNCULUS. 69 
In P. obsoletus, Goldfuss,' the shell is oblique, and more oval and rounded in 
form than in P. sub/evis. 
P. subpulvinatus, V Archiae,’ from the Tourtia of Tournay, is also more oblique 
and has the posterior border more rounded. 
For the relation of this species to P. winbonatus, Sowerby, see p. 70. 
The two examples described by Keeping (vide supra) from the Lower Green- 
sand of Upware appear to differ from P. sublevis in being less inflated and 
in having a higher area, but the specimens are not sufficiently perfect to allow me 
to give a definite opinion on their affinities. 
Types.—From Blackdown ; in the British Museum. 
Distribution.—Greensand of Blackdown (zones xi and xii); Lower Gault (zone 
vi) of Folkestone (fide Price), 
PECTUNCULUS UmMBONATUS (Sowerby), 1817. Plate XIV, figs. 8 a—c, 9a—e, 10 a—e, 
iets 
1817. Carprum umBonatum, J. Sowerby. Min. Conch., vol. ii, p. 128, pi. elvi, 
figs. 2—4, 
1824. Precruncunus umBonarus, J. de C. Sowerby. Ibid., vol. v, p. 113, pl. eeelxxii, 
fig. 3. 
1854. = -- J. Morris. Cat. Brit. Foss., ed. 2, p. 220. 
1868. — — A. Briart and F. L. Cornet. Descript. de la Meule 
de Braequegnies (Mém. Cour. et Mém. 
des Say. étranvers, Acad. Roy. Belg., 
vol. xxxiv), p. 61, pl. v, figs. 19, 20 ? 
Non 1837. -- — A. Goldfuss. Petref. Germ., vol. il, p. 160, pl. 
exxvi, fig. 2. 
?— S41. -— -— F. A. Rémer. Die Verstein. des norddeutsch. 
Kreideformat., p. 68. 
— 1846. — _ A. E. Reuss. Die Verstein. der béhm. Kreide- 
format., pt. ii, p. 9, pl. xli, 
fig. 20. 
— 1857. -- _ J. W. Salter. Quart. Journ. Geol. Sov., vol. 
xiii, p. $6. (Por remarks on 
this form see Jukes-Browne, 
Geol. Mag., 1898, p. 29.) 
Description.—Shell rather inflated and more or less circular or slightly sub- 
quadrate, usually a little higher than long, nearly equilateral. Anterior margin 
3? 
1 *Petref. Germ.,’ vol. ii (1837), p. 160, pl. exxvi, fig. 4; Geinitz, “ Das Elbthalgeb. in Sachsen” 
‘ Paleontographica,’ vol. xx, pt. i (1873), p. 228, pl. xlix, figs. 7—11. 
2 «Mém. Soc. Géol. de France,’ ser. 2, vol. xii (1846), p. 306, pl. xv, fig. 2. 
