106 INVERTEBRATA. 



Pecten orbicularis, Sowerby, var. MAGNUS, var. nov. 

 (Plate v., fig. 1.) 



P. orbicularis, Sby., Mm. Con., f. 186. 



d'Orb., Terr. Orel, pi. 433, f. 14—16. 

 P. Cottaldinus, Cat. Foss. Mus. Practical Geology, 1878, p. 13 



(non d'Orb.). 



A shell variously named in English and German collections 

 P. ductus, crassitesta, junr. orbicularis and Cottaldinus. I cannot 

 distinguish it from the true Pecten orbicularis of the Upper Green- 

 sand (Warminster, &c). 



P. ductus {crassitesta) has a much thicker shell with straight 

 hinge line, the ears being less prominent than in orbicularis, and 

 the shell is marked on one or both valves with delicate radiating 

 depressed strise. 



Pecten Cottaldinus is quite a different shell, having very unequal 

 ears, and also ornamented with radiating strise (see d'Orb., Terr. 

 Cret, p. 590, pi. 431). 



It is worth notice that Pecten ductus is absent from the Wicken 

 Beds. 



Our shell is considerably larger than the original type and de- 

 serves the separate varietal name magnus, 



Pecten orbicularis (Sow.), var. magnus nob. 



Localities. Up ware, Potton, Ely (Neocomian), Hythe, Ather- 

 field, Tealby. 

 S. Europe. France, Switzerland, &c. 



Pecten (Neithea) Morrisii, Pictet and Renevier. 



Pecten quinquecostatus, J. Sowerby, Geol. Trans., 1836, Roemer, 



Forbes and others [non P. quinquecos- 

 tatus, Sby., Min. Con.]. 

 Janira Morrisii, Pictet and Renevier, 1858. Pal. Suisse, Etage 

 Aptien, St Croix, p. 128, pi. 19, f. 2. 

 „ „ Pictet and Campiche, Terr. Cret, St Croix, 



p. 244. 



A shell very near to Neithea quinquecostata (Sby.), distinguished 

 from it principally by the character of the areas external to the 



