892 MURICIDiE. 



Buccintimhrece'^ Couch, Cornish Fauna, pt. '2, p. G4 (fry). — Johnston, Ber- 

 wick. Club, vol. i. p. '238 (from type). 

 Tritonium Ascaiiuis, Middenh. Malacoz. Ross. pt. 2, p. 177. 



The swollen penult volution of this solid little shell 

 distinguishes it at once from the preceding ; its coarser 

 sculpture, paler aperture and anterior spot, render its dis- 

 crimination fi'om the succeeding species a task of equal 

 easiness, even where it exhibits, as is exceptionally the case, 

 a varix similar to the characteristic one of that shell. 



It is more or less opaque, a little glossy, of a shape pass- 

 ing from oval-conical (the ordinary form) to ovate-acute 

 (the stunted form), and of very variable painting. On the 

 peculiarly broad and prominent white varix that strengthens 

 the outer lip of the adult, and contracts the size of the 

 aperture, are to be traced, though at times somewhat 

 faintly, the commencement of three chestnut or brown 

 sometimes interrupted bands, one at a little distance from 

 the suture, one just below the middle, and the third one 

 basal ; of these, which do not always even traverse the 

 body throughout (for sometimes the entire exterior, the 

 varix excepted, is of an uniform brown or orange hue ; the 

 ground of the ordinary or banded variety is impure white) 

 one or both of the upper ones wind, wholly or partially, 

 round the spire, whose fine apex is sometimes purple. The 

 more or less curved abruptly prominent fold-like ribs, that 

 traverse the shell lengthways, and extend to the base of 

 the body-whorl, are rendered somewhat nodulous by very 

 numerous depressed spiral costelhe, which are so closely 

 disposed, that the intervals at times seem mere sulci ; the 

 intervals of the ribs, which arc also numerous, and have a 

 tendency to dilate, in some specimens, below the middle of 

 the smaller turns, are of moderate width, and often, indeed, 

 are broader than the ribs themselves. The spire is about 



