LAMELLIBRANCHIATA. 105 



become double and triple towards the border by the development 

 of side ridges. 



Range. Neocomian — Chloritic Marl. 



Localities. Upware, Atherfield, Folkestone (Gault), Cambridge 

 Greensand. 

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

 ments de l'Aube and cle la Meuse. 



Pecten elongatus, Lamarck. 



Pecten elongatus, d'Orb., Pal. Fr., Terr. Cre'l, pi. 436, f. 1—4. 



Locality. Brickhill. 



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

 S. Europe. France, Belgium. 



Pecten Dutemplei, d'Orbigny. 



Pecten Dutemplei, d'Orbigny, 1845, Terr. Cre't, p. 596, pi. 433, 

 f. 10. 

 „ Aptiensis, Pictet and Roux, 1853. 



„ Dutemplei, Pictet and Campiche, Pal. Suisse, Terr. Cret. 

 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. 



