SCISSURELLA. 545 



of them, since those lying above it are more obliquely 

 arcuated than those below it (which otherwise, both in 

 strength and approximation, they exactly resemble), whilst 

 those inclosed within it lean in an opposite direction to the 

 two other series. The whorls, which are three in number, 

 increase with some rapidity, and terminate in a flattened 

 apex ; although not much elevated, they are tolerably 

 large, and being depressed above, but well rounded below, 

 appear somewhat scalariform ; the body- volution slopes 

 with a gentle convexity from the well-marked suture. The 

 base is not compressed, but rounded, and swells out near 

 the lij) to an extent almost equal to the rise of the spire ; 

 the axis is perforated by a simple and wide-mouthed um- 

 bilicus. The large aperture which is obliquely set, and of 

 a depressed rounded-subquadrate form, bulges out consider- 

 ably near the outer anterior corner ; it is broader than it is 

 long ; the length occupies more than one half of the entire 

 shell, the breadth is rather superior to one half the basal 

 diameter. The outer lip, which greatly recedes in front, 

 is simple, acute, and much arcuated, but its continuity is dis- 

 turbed by the fissure, where it pouts out in an acuminated 

 form, both above and below, becoming in the latter position 

 peculiarly arcuated and effuse. The pillar-lip, which is 

 more or less broad and flatly reflected, yet not appressed, 

 is refuse behind ; it is short, and is either straight or leans 

 away from the outer lip. The breadth of most of the 

 specimens hitherto obtained is not much more than the 

 tenth of an inch, and this is nearly twice the length, which 

 does not very much exceed two-thirds of a line. 



This beautiful but minute shell was discovered in 180.9 

 by the Rev. Dr. Fleming, who found it in sand from Noss 

 Island, one of the Zetland group. Mr. Barlee has taken it at 

 East Tarbert (Long Island), Loch Fyne, and on the north 



VOL. II. 4 a 



