380 SPECIES OF THE SYSTEMA. 
specimens, since we are assured by his catalogue of the presence 
of examples in his cabinet. 
Helix stagualts, 
Linnzus haying remarked that he had designated two Helices 
by the same appellation, has changed in his manuscript the 
name of the present and less known one into Bastert. Gmelin, 
who perceived the repetition of the same name, having noticed, 
probably, that although standing before the other stagnalis in 
the numerical succession of species in the twelfth edition of 
the ‘Systema,’ it was posterior to it in date of publication by 
several years, altered it to stagnorwm, but added nothing else 
to our information respecting it: neither, indeed, have I dis- 
covered any further details in the pages of the older concholo- 
gists. In the ‘ Zeitschrift fiir Malakozoologie’ for 1845 (p. 87), 
Menke has published a Paludina stagnalis as the Linnean 
shell, with the synonyms Cyclostoma acutum, Draparnaud 
(Moll. France, pl. 1, f} 23), Paludina acuta, Deshayes (Anim. s. 
Vert. vol. viii. p. 521), Paludina stagnorum, Turton (L. and 
F. W. Shells, f. 123), references which Philippi (Enum. Moll. 
Sicil. vol. i. p. 148), on the contrary, attributes to the Linnean 
Turbo thermalis. 
One cannot wonder, indeed, that so much uncertainty pre- 
vails, since the meagre description in the ‘Systema’ was only 
illustrated by a reference to a most futile attempt at delineation 
and a bald and unmethodical description in Baster’s ‘Subseciva’ 
(i. p. 77, pl. 7, f. 4). The shell represented in that work was, 
as we learn from the text (for the only information to be gleaned 
from the drawing is that the whorls were slightly ventricose), 
about the eighth of an inch long, and of nearly half that breadth, 
had six volutions which terminated in an obtuse point, and 
were very delicately striated in a longitudinal direction ; it was 
found in estuaries, with its surface, for the most part, incrusted 
with decayed vegetable matter. These characters certainly 
indicate a Paludinella (or Hydrobia), but the precise species 
could scarcely be positively determined from such scanty de- 
tails. The surmise of Menke was perhaps, then, venturesome, 
but assuredly comes very near the mark, if not absolutely 
