lEUCOZONIA. 149 



nodose, distant, spiral carinte in front of the peripheral angulation, 

 and sharply depressed half way between the latter and the end 

 of the canal ; surface of the whorls bearing several more or less 

 conspicuous, undulating spiral lineations ; aperture ovate, broad 

 in front ; outer margin thin, bearing a small tooth-like projection 

 anteriorly, lirate within, grooved posteriorly ; inner margin 

 furnished with one or two salient, elongate ridges bordering the 

 posterior channel, excavated ; columella umbilicate, smooth, and, 

 typically, carrying four plications, the one in front being smallest ; 

 anterior canal short, broad, and slightly bent. 



This species is exceedingly variable, but the specimens commonly 

 found in the West Indies, and particularly from St. Vincent, 

 are typical, and are almost identical with the specimen from 

 the Pliocene beds of the Chatham Is., in the Museum collection. 

 Living examples have been obtained from the west coast of 

 Africa, Florida, and Brazil, as well as in the West Indies. 



Compared with Latirus barclayi, Reeve, the whorls of the 

 spire are similarly ornamented, but the aperture of the last- 

 mentioned species is narrower, the columellar plaits are smaller 

 and more numerous, and are not in the same position, whilst the 

 canal is very much longer. 



This shell is commonly known as L. cingidifera, Lamarck, but 

 the name here adopted has priority. This fact has been recognized 

 by authors,' but L. nassa appears to have been ignored because 

 Grnelin included other species in his description and references, 

 a view which cannot be entertained. Following usage, we consult 

 the first reference given by Gmelin,- which is undoubtedly the 

 species under description, and which should therefore bear the 

 name of nassa. 



Dimensions. — Length 49 mm.; breadth 27 mm.; length of 

 aperture and canal 27 mm. 



Form, and Loc. — Pliocene : obtained from a well-digging ten 

 feet in depth, Chatham Islands. 



G. 9672. An example of the adult. 



Transferred from the Mmeum of Practical Geology. 



' E.g. Tryon, Manual of Conchology, vol. iii. 1881, p. 95. 

 2 Lister, Hist. Coucb. lib. iv. 1688, Xo. 828, fig. 50; also ed. 1770 (same 

 No. and fig.). 



