402 SPECIES OF THE SYSTEMA. 
described in that publication were the original types, having 
been referred to as such in the earlier edition of the ‘ Systema,’ 
where the obnoxious “viridi” did not occur. Judging from 
the dimensions “ magnitudi pisi” (M. U.), and the smoothness 
of the outer lip, “labium exterius—utrinque leve” (M. U.), 
one is inclined to suspect that it was a member of the genus 
Neritina: Récluz, however, a high authority, has doubtfully 
suggested that it may have been the fry_of Nerita Rumphi. 
Although stated to be only the size of a pea, a large Nerite 
figured by Chemnitz in the tenth volume of his ‘Conchylien 
Cabinet’ (pl. 165, f. 1594, 5), has been ascribed to it, as a 
variety, by Gmelin: he, too, possibly conjectured that bidens 
had been constituted from immature examples. 
fevita viridis. 
Since we are assured by his lists that Linneus possessed an 
example of this shell, and one species only in his entire collec- 
tion will agree with the description, no reasonable doubt of the 
typical authority of these individuals can be entertained. The 
specimens belong to tlie Neritina generally recognised as the 
Linnean viridis, and not to that closely-allied congener Ran- 
giana, which has been sometimes confused with it. The Neri- 
tina, f. 24 of Sowerby’s ‘ Conchological Illustrations,’ may be 
cited as illustrative; but the ordinary white markings are not 
exhibited there, and the dark lines are more conspicuously 
displayed than is usual. 
Perita birgtnea, 
The Neritina virginea, as it originally appeared in the tenth 
edition of the ‘Systema,’ was accompanied solely by two re- 
ferences, Bonanni (f. 204) and Petiver (pl. 11, f. 3): the former of 
these exhibits the Neritina virginea (var. Brasiliana) of authors, 
the latter Neritina strigilata of Lamarck. The description, 
although brief, clearly points out the former as the more typical 
form, by the expression “labio interiore gibbo,” the gibbosity 
