340 



CRETACEOUS LAMELLTBRANCHIA. 



Inoceramus corrugatus, sp. nov. Text-fig-. 97. 



Remark*. — This species is at present known only by a small portion of one 

 valve. It is of the same general type as I. digitatus, Sowerby, I. pinniformis, 

 Willett, and I. subcardissoides, Schliiter, but owing- to the presence of broad, 

 strong radial folds the radial ribs are arranged in groups of four or five. The 



Fig. 97.— Inoceramus corrugatus, sp. nov. Upper Chalk, Wouldham Cement Quarry, Grays. British 

 Museum, No. L22528 (discovered and presented by Col. C. E. Shepherd). Natural size. 



concentric folds are strong and have a steep ventral, and a gentle dorsal slope. 

 The growth-lines are distinct and regular. I. corrugatus and the other species 

 mentioned may be compared with I. lezeimensis, Decocq, 1 which is of the same 

 type as I. Lamarcki but possesses two radial folds due to the presence of a medial 

 sulcus. 



Distribution. — Upper Chalk, Wouldham Cement Company's Quarry, Grays, 

 Essex. 



1 Barrois, ' Ann. Soc. geol. du Nord,' vol. vi (1879), p. 455, pi. 5, figs. 1, 2. 



