400 SPECIES OF THE SYSTEMA, 
*evita lacustris. 
This inadequately described shell could not possibly have 
been identified from any particulars furnished by Linneus. 
The meagre account originally published in the tenth edition 
of the ‘Systema’ was reproduced verbatim in the ‘Fauna 
Suecica;’ the only addition in the final issue of the ‘Systema’ 
being the two references to the last-named work and to Gualtier, 
and the words “et fontibus calidis” derived from the latter. 
Had it not been for the fluviatile locality and the cited 
engraving one might reasonably have conjectured that it was 
a Littorina allied to the preceding species; both these, how- 
ever, suggest its allocation in the genus Neritina. The shell 
delineated by Gualtier, which reminds us of one of the many 
varieties of N. meridionalis, is stated to have been “ subnigra, 
candidis punctis aspersa,’ language which scarcely harmonises 
enough with the “cornea” of the diagnosis to render the 
illustrative reference decisive as to the species. The only 
Swedish Neritina recorded by Nilsson is the fluviatilis ; so that 
the N. lacustris of the ‘ Fauna,’ at least, was in all probability 
only a variety of that many-coloured shell, an opinion corro- 
borated in some measure by the circumstance, that although 
Linneus has certified his possession of an example, the only 
member of that genus in his cabinet which is not absolutely at 
variance with the recorded features is a remarkable glabrous 
horn-coloured variety of that well-known shell, whose aspect 
differs so strikingly from the rougher and variegated specimens 
obtained in “ Kurope cataractis,’ that its essential identity 
might reasonably have been doubted. 
PMevita pulligera. 
The abraded remains of egg-cases are often perceptible upon 
specimens of the larger Neriting, and are graphically enough 
depicted by our author in the three last lines of his description. 
The name pulligera (“ pullos in dorso teste gerit”’) was bestowed 
from this circumstance, in the belief that the young fry, thus 
