ADDITIONS. 125 



is nearly flat, and the broad radial ribs are much less distinct than on the left 

 valve ; numerous fine concentric ribs are present, and are widely spaced on the 

 early part of the valve, but become closer together on the later part. 



Pecten (Chlamys) cretosus, Defrance. 



Vol. I, p. 179, line 17, delete "Clarendon and Alderbury (Salisbury)." 



Pecten (^Equii'Ecten) campaniensis, d'Orbigny. [Vol. I, p. 192.] 



A specimen of this species has been found by Dr. Rowe in the zone of 

 Micraster cor-testudinarium of Dover. 



Lima (Limea?) sp. Plate LXI, fig. 19. 



[Omitted from Vol. II, p. 52.] 



A few examples of a species which resembles Limea granulatissima ) Wo\lem&rm, 1 

 have been found in the Speeton Clay (zone of Belemnites lateralis) of Speeton. 

 Only a young individual is figured by Wollemann, so that exact comparison 

 cannot be made at present. 



Sub-genus — Pseudoptera, Meelc. 



When describing the species of Pseudoptera (pp. G3-69) I regarded it as a 

 sub-genus of Pteria. Ligament-pits have not been seen in any English specimens, 

 but their presence was noticed by Gueranger 2 and by Peron 3 and indicates that 

 Pseudoptera, cannot be associated with Pteria, but should probably be regarded as 

 a sub-genus of Gerrillia. 



Gervillia Forbusiana, d'Orbigny. 



[Vol. II, p. 85, pi. xi, figs. 26, 27; pi. xii, figs. 1—5.] 

 This species belongs to the sub-genus Ensigervilleia of Dietrich. 4 



1 ' Bivalv. u. G-astrop. d. deutscli. u. liolliiiidisch. Neocoms ' (1900), p. 37, pi. ii, figs. 4, 5. 



2 'Album Pak'ont. de la Sartlie ' (1867), pp. 17, 20, pi. xxii, figs. 9, 10; pi. xxv, figs. 10, 11 

 Woods, 'Palseont. U. Cret. N. Nigeria' (1911), p. 278, footnote 1. 



3 "Descript. Braeli. etc., Terr. Cre't, Tunisie" (1890—91), p. 238. 

 * 'Centralbl. fur Min., etc.' (1910), p. 235. 



