372 MURICID^E. 



which is composed of six or seven turns, that are neither 

 remarkable for length or volutional increase, are more or 

 less scalariform, being abruptly and perpendicularly elevated 

 below, and more or less horizontally flattened above, and 

 profoundly divided by their broad sutural line. The basal 

 declination of the body is gradual and but little rounded. 

 In adult individuals, where the anterior extremity of the 

 mouth is rendered tubular by the confluence of the two 

 lips, and the broad external varix somewhat contracts the 

 cavity, the aperture is rather small and simply oval ; in 

 the young, where the final development has not yet taken 

 place, it looks much larger, and is acutangular below. 

 Measuring from the upper corner of the orifice to the 

 extreme tip of the canal, which is a little recurved and 

 bends slightly to the right, about four-sevenths of the 

 ventral length is occupied by the mouth. Rather obscure 

 dentiform crenations stud the much arcuated inner margin 

 of the right lip, which is rendered very broad and solid by 

 the external varix, and is not armed, as in a somewhat 

 similar looking foreign shell, by any horn-like protrusion. 

 The inner lip, which, as well as the throat, is usually snow- 

 white (though the latter is beautifully tinged with rose- 

 colour or purplish in some few examples), is smooth, nearly 

 perpendicular, somewhat flattened, and only slightly in- 

 curved near the middle : the pillar lip is appressly reflected 

 above, but becomes erect towards the canal. Montagu 

 has recorded examples that measured an inch and three- 

 quarters in length, and nearly an inch in breadth, but such 

 are very scarce in collections. 



A somewhat dwarfed variety exists, in which the whorls 

 are merely subangulately ventricose, the varices do not 

 foliate at all, but look as if worn down, and the finer scales 

 are scarcely at all developed. 



