214 CRETACEOUS LAMELLIBRANCHIA. 
Janiva quadricostata, and many later writers have followed d’Orbigny in referrin g 
that form to Sowerby’s species; but it was shown by Pictet and Campiche, and 
also by Briart and Cornet, that d’Orbigny’s species is distinct from Sowerby’s. 
The latter differs from the former in being of larger size, in having much larger 
ears and a longer hinge-line, in the anterior and posterior areas sloping outwards, 
in the larger apical angle (seen especially in the left valve), and in the greatest 
leneth of the left valve bemg above the middle line. The Senonian form figured 
by @Orbigny was named Jamra Faujasi by Pictet and Campiche,’ and is regarded 
by Choffat® as identical with regularis of Schlotheim. 
Fia. 5.—Pecten (Neithea) quadricostatus, Sow. Upper Greensand, Warminster. York Museum. 
Interior of left valve. Natural size. 
Types. 
The specimens figured by Sowerby are in the British Museum—fig. 1 is 
from the Upper Greensand of Haldon, fig. 2 from the Upper Greensand of Chute 
Farm, Warminster. The example figured in the ‘ British Mineralogy’ is from the 
Upper Greensand of Stourhead. 
Distribution.—Upper Greensand (zone of Schlenbachia rostrata) of Blackdown 
and the Isle of Wight; Upper Greensand (zone of Pecten asper) of Haldon, Cerne 
Abbas, Meleombe Bingham, Egeardon Hill, Maiden Newton, Ballard Down 
(Swanage), Warminster, and Ventnor. 
Prcotren (Nurrupa) sexcostatus, Woodward, 1833. Plate XL, figs. 10—15; Plate 
XUI, figs. 1—10. 
? 1822. Proren quinquecosrata ?, G. Mantell. Foss. S. Downs, p. 128, pl. xxv, 
fig. 10. 
P — — TRIPLICATA, Mantell. Ibid., p. 128, pl. xxv, fig. 9. 
1833. -- sEexcosratus, S. Woodward. Geol. Norfolk, p. 48, pl. v, fig. 29. 
1 «Foss. Terr. Crét. Ste. Croix” (‘ Matér. Pal. Suisse,’ ser. 5, 1870), p- 253, 
* «Waune Crét. Portugal,’ vol. i, ser. 4 (1901-2), p. 149. 
