CHEMNITZIA. 427 



rather opake white. The mantle is even with the shell, 

 scarcely showing a fold at the upper angle of the aperture. 

 The rostrum is very slender, not cloven, but truncate at the 

 end, and, as usual, on the march precedes the foot. The ten- 

 tacula are rather long, slender, not particularly divergent, 

 and have but narrow margins for the auriform folds; they 

 are taper, bevelled, and terminate in prominent white tips; 

 the eyes are not very close together at the internal bases. 

 Foot short, narrowish, rarely extending when fully deployed 

 much beyond the body volution, truncate in front or very 

 little concave, with short auricles, and a little contracted 

 below them, carrying on a simple upper lobe, at the junction 

 of the foot with the body, a thin, pear-shaped, light corneous, 

 obliquely striated operculum ; the foot has a rather obtuse, 

 though lanceolate, termination. 



I have reproduced this species, partly with the view of cor- 

 recting some slight errors, but principally to place it in imme- 

 diate view, for comparison with its tumid variety, and with 

 the next species, the Chemnitzia indistincta, and its variety 

 that has been named C. clathrata, all of which have been 

 strangely jumbled together ; but very large series of both 

 species and their varieties have, I think, enabled me to unravel 

 various misapprehensions. With respect to the shell of the 

 present species, it has only one well-marked tumid variety, 

 which, as regards the animal, differs in 110 respect from its 

 chief, as the posterior volutions of both, in the shell, are of a 

 dark lead-colour ; but the variety is invariably of larger size ; 

 the whorls, though the same in number, are more tumid, and 

 the body volution is more than half the whole length of the 

 shell ; there is rarely on the body and next turn more than 

 one well-pronounced row of crense, and a tooth is always 

 visible in the aperture. I have a fine series of more than 

 twenty examples of the variety, and 100 of the type, all of 

 which have been examined alive. 



It is difficult to say whether Montagu's figure represents 

 the shell with the flat or tumid volutions, but as far as the 

 indifferent engraving will allow one to judge, I should guess 

 it to be the tumid variety. I believe, however, all collectors 



