NATICA. 327 



erroneous conviction, that the species thus designated, was 

 the glaucina of Linnreus. 



The shell is not depressed, but nearly globose, and in 

 the adult is about equally as broad as long ; it is mo- 

 derately strong, yet not very solid, more or less glossy, 

 smooth, or nearly so (for there are very many obscure 

 fine wrinkles of increase), and adorned below the junction 

 of the whorls with a single narrow band of obliquely 

 longitudinal flexuous chestnut streaks, on a ground of 

 pale livid flesh, or olivaceous grey, that becomes whiter 

 upon the base, and turns paler, for the most part, in the 

 more aged examples. A very short upper rim of white 

 usually margins the whorls, and renders the strongly pro- 

 nounced suture more conspicuously distinct. The body 

 is very large, and is much swollen, yet is flattened in some 

 slight degree in the middle ; its base is not at all peaked 

 nor produced, and slopes rotundately, but rather abruptly, 

 to its anterior termination. The spire, which occupies 

 nearly two-sevenths of the dorsal length, is composed of 

 five or five and a half quickly tapering short turns, whose 

 volutional increase is rapid but equable, the penult not 

 being strikingly longer than the preceding coil ; they are 

 of abrupt elevation (so that they do not appear to shelve 

 into each other as in Alderi), are much rounded, and are 

 neither angulated, flattened, nor retuse above, as in certain 

 Natic<B ; the apex is very small, but not much projecting. 

 The mouth, which is half moon-shaped, or of a very 

 narrow subovate form (being more broadly rounded ante- 

 riorly), occupies nearly two-thirds of the ventral length ; 

 the throat is smooth, and stained with chestnut or livid 

 brown. The acute and simple outer lip almost forms a 

 semicircle, and arches out from the body at nearly a right 

 angle. The umbilicus is large, open, and rather obscurely 



