154 Mr Tawney, On the Upper Bar/shot Sands d-c. [Nov. 28, 



existence, it is not cited in our list. The type occurs in much 

 lower beds in France.] 



[G. arenaria, Forbes, labelled in the Edwards collection as 

 from Long Mead End, is not from the U. B. sands. This shell 

 from the Lower Headon seems frequently determined as G. deper- 

 dita; we fell into the error ourselves ; it is a higher and flatter 

 shell] 



Mactra filosa, Edw. MS. We have one specimen which we 

 consider the same as the unique example from the Long Mead 

 End sands on which Edwards founds his name ; it is a little more 

 trigonal than M. fastigiata, Ed. MS., but until more specimens 

 are found its title to specific rank is uncertain. Some dwarfed 

 poorly preserved specimens in the Edwards collection are labelled 

 as from Colwell Bay, but from the character of the matrix they 

 perhaps come from Long Mead End. 



\M. fastigiata occurs in the Beacon Bunny clay.] 



Gytherea Suessonensis, Desh. = C. tenuistria, Sow. This shell, of 

 which we have 4 examples from the Long Mead End sands, is 

 determined in the Edwards collection as G. suborbicidaris, Ed. 

 MS., but it is evidently of the same species as that which we 

 collected in the Beacon Bunny clay below, and which Edwards 

 has determined as G. tenuistria, Sow. This is a variable shell if 

 we adopt the limits allowed to it in his collection ; we have here to 

 do with the variety wider in antero-posterior direction. It differs 

 from C. suborbicularis, Ed. MS., in being a little more inflated, the 

 lunule more impressed makes the outline there a little straighter, 

 the umbos a little more turned inwards, the lower margin less 

 curved, the growth stria) coarser, and the ligament was less 

 exposed. 



Gorbida Edwardsii, n. sp. A small corbula is abundant in the 

 Long Mead End sands, which Edwards in his collection has 

 determined as C. nitida, Sow.; he has it also from Roydon. We 

 remark that Sowerby (about 1823 A.D.) describing C. nitida, says it 

 was " first observed by Prof. Sedgwick in several parts of the Isle 

 of Wight below the upper freshwater formation." At that time the 

 Hamstead and Headon Hill beds were not separated, so that the 

 stratigraphical position is not trustworthy. The probability there- 

 fore is that the shells were collected at Hamstead, and are the 

 G. Vectensis, Forbes; this is almost certain on comparing Sowerbv's 

 figures, Min. Conch, iv. p. 85, pi. 162, figs. 1 — 3, they agree 

 entirely with the Hamstead species. Prof. Morris in editing the 

 Appendix to Forbes' Memoir on Isle of Wight, p. 145, suggests 

 that the new name was a synonym of Sowerby's. The Wood- 

 wardian Museum possess specimens collected by Sedgwick about 

 1820 at Hamstead, and they have always borne the name of 

 G. nitida, Sow. Though there is no record of their being the 



