972 HELIX. 



BALTHiCA. 187. Shell imperforate, ovate, acumi- 

 nated, with elevated wrinkles, and the aper- 

 ture large and ovate. 



Helix Balthica. Linnceus Syst. Nat. p. 1250. Gmelin, 

 p. SQQS. 



Inhabits the Baltic. Limiaus. 



Linnaeus has not mentioned the size, or given any reference 

 to a figure, and this species has not been noticed by any 

 subsequent author. In the Fauna Suecica it is stated to be 

 pellucid, with four whirls, and that it has a black inhabitant 

 with two teutacula. 



NERITOIDEA. 188. Shell imperforate, convex, lon- 

 gitudinally striated, with the lip reflected 

 over the uaibilicus, and the aperture roundish. 



Helix neritoidea. LimicEus Syst. Nat. p. 1250. Gmelin, 



p. 3663. 

 Gualter, t. 64. f. I. 



Inhabits the Baltic. Linnaus. 



This species is said to be of a livid colour, with more than 

 forty striae. Gualter, t. 64. f. I, to which Linnaeus has re- 

 ferred, is a magnified figure of a minute shell, which is gra- 

 nulated by cancellated striae, and is said to have a large white 

 aperture. 



PERSPicuA. 189. Shell imperforate, convex-ovate, 

 with crenulated striae, and the spire slightly 

 produced ; aperture roundish and very large, 

 so as to expose the whole inside. 



Helix perspicua. Linnoius Syst. Nat. p. 1250. Gmelin, 

 p. 3663. 



Inhabits the Mediterranean. Linnaus. 



Shell about an inch in diameter, and much depressed, but con- 

 vex on both sides, and of a pale brownish white colour ; it 

 has three and a half whirls, which are strongly marked with 

 crenulated spiral strise, and the spire is slightly elevated ; 

 the inside is striated, and somewhat iridescent ; though more 

 nearly allied to Haliotis than Helix haliotoidea, it is very 

 different from the imperforated species of that Genus, and 

 in a Linnaean arrangement will hardly stand any where better 

 than in the place which Linnaeus has assigned it. 



