192 MYTILID^. 



fathoms (M' Andrew and E. F.) ; and at Milford Haven. 

 Mr. Bean states that it occurs, though rarely, at Scar- 

 borough, a locahty not consistent with its known distri- 

 bution. In from three to ten fathoms among weeds, at 

 Clew Bay in the West of Ireland (R. Ball, W. Thompson, 

 and E. F.); Youghal, very rare (R. Ball). 



It is a member of the Lusitanian fauna, and ranges into 

 the Mediterranean, where it is common. 



M. Ballii, Brown. 



Modiola Ballii, Brown, Illust. Conch. G. Brit, and Irel. p. 132, pi. 42, f. 34, 35. 

 „ vesiita, Thompson, Ann. Nat. Hist, vol. xv. p. 318. 



Most unfortunately the single specimen from which this 

 species was described and figured, cannot at present be 

 found by its possessor, Mr. R. Ball, who courteously reply- 

 ing to our inquiries for further particulars to verify its in- 

 digenousness, states, that it came into his possession, appa- 

 rently quite fresh-looking, along with other undoubtedly 

 Irish shells said to have been found in Ardmore Bay. AVe 

 cannot venture to include this shell among our native 

 species on the evidence of report alone ; we transcribe, 

 however, the description published by Captain Brown from 

 the lost specimen. 



" Shell transversely oblong-ovate ; umbones placed very 

 near to one side ; a slight groove or furrow^ emanates from 

 the umbones, and terminates in an oblique line on the mar- 

 gin of the anterior side, on which the colour is golden- 

 yellow ; covered with a very glossy olivaceous epidermis, 

 which in certain lights exhibits a metallic lustre ; inside 

 highly pearlaceous, with transverse wrinkles towards the 

 extremity ; the surface exhibiting gold and coppery 

 metallic reflections, and studded -with a number of small 

 circular pits like those left by the small-pox." 



