LAMELLIBRANCHIATA. 105 



become double and triple towards the border by the development 

 of side ridges. 



Range. Neocomian — Chloritic Marl. 



Localities, Up ware, Atherfield, Folkestone (Gault), Cambridge 

 Greensand. 

 S. Europe. Presta (Aptien), P. and C; Gault of depart- 

 ments de I'Aube and de la Mouse. 



Pecten elongatus, Lamarck. 



Pecten elongatus, d'Orb., Pal. Fr., Terr. Cr^t, pi. 436, f. 1—4. 



Locality. Brickhill. 

 N. Europe. Dresden, (Planerkalk), etc. 

 8. Europe. France, Belgium. 



Pecten Dutemplei, d'Orbigny. 



Pecten Dutemplei^ d'Orbigny, 1845, Terr. Cre% p. 596, pi. 433, 

 f. 10. 

 „ Aptiensis, Pictet and Roux, 1853. 



„ Dutemplei, Pictet and Campiche, Pal. Suisse, Terr. Cr^t. 

 St Croix, p. 199, pi. 172, f. 1—4. 



Distinguished from the other species of the Lnterstriatus group 

 by the nature of the ornament on the buccal ear of the larger 

 valve. 



Localities. Upware, Potton, Farringdon, Atherfield?, Spee- 

 ton(?). 

 8. Europe. Perte du Rhone (Aptien), d'Ervy (Gault). 



Another Pecten from Upware is distinguished by its numerous 

 ribs — over 100. Its ornament is of like nature to that of d'Orbig- 

 ny's P. Robinaldinus {Terr. Cret, pi. 431, f. 4), but more delicate. 

 It approaches the " type a cotes nombreuses " of Pictet and Cam- 

 piche from the Urgonien, but that form has only about 80 ribs. 

 Our specimen is too imperfect for satisfactory determination or 

 description. 



