oie SPECIES OF THE SYSTEMA. 
significant numerals fully and distinctly inscribed upon one of 
the specimens; for very rarely is any writing to be found on 
the smaller shells of the collection. Da Costa and Montagu 
had surmised the identity of that common British snail with 
the Itala of Linneus. 
Helix Lusttantea, 
Miiller and Schroter have not attempted to determine this 
ambiguous shell; Chemnitz, attending to the cited figure, 
rather than to the language of our author, has fancied he 
recognised 1t in what he has called H. Guineensis contraria ; 
Gmelin, without altering the original description, has quoted 
the Chemnitzian along with other representations of reversed 
Ampullarie, as illustrative ; in this last proceeding he has been 
followed by Dillwyn. Karsten’s unillustrated ideal is too 
baldly described for recognition. Lamarck has referred the 
species to his Ampullartia Guinaica. No sinistral Ampullaria 
is to be descried in the typical collection; nor, indeed, did I 
expect to find one, since Linneus has never failed to point out 
the circumstance of the whorls being reversed (as in Turbo 
bidens, Helix perversa, &c.). The presumed identification has 
been solely based upon the belief that the cited engraving of 
Gualtier (t. 2, f. T) represented the object described by Linneus, 
a conclusion not warranted by the language of the ‘ Systema,’ 
for the volutions in the species delineated are coloured and 
banded, not simply “‘flavescente—albidis,” and the shape is sub- 
clobose, not merely “ convexa, obtusa,” terms used by Linnzus 
to indicate the depressed-orbicular contour of H. citrina. The 
drawing was doubtlessly referred to from the resemblance it 
exhibits in size, umbilication and general aspect to the snail 
which our author desired to indicate, but was evidently not 
regarded by him as an accurate representation, since in his own 
copy of Gualtier, where he has attached to the other figures 
the names used by himself in the ‘Systema,’ he has passed 
over that one without comment. The cabinet of the illustrious 
naturalist dispels all doubts upon the subject. Two specimens _ 
of the Helix Algira of Draparnaud are there present; the peri- 
