HELIX. 963 



stitutes half the length of the shell. I hard^iy know what 

 Linnaeus means by ' sub-angulated' in his specific character, 

 unless he a,lludes to a gibbosity, which in old shells is not 

 unfrequent on the body-whirl. JI. Corvus was first figured 

 separately by Martini in the Berlin Magazine, and appears 

 to dift'er in nothing from some of the most common appear- 

 ances of H. stcignalis. 



FRAGiLis. 169. Shell imperforate, ovate-subulate, 

 taper, pellucid, and the aperture ovate-ob- 

 long. 



Helix fragilis. Linnaus Syst. Nat. p. 1249. Schroeter 

 Fluss. p. 309. t.7. f. 8, and Eiiil. ii. p. l6s. Gmelirt, 

 p. 3658. 

 Martini Bed. Mag. iv. t. 9. f. S5. 



Inhabits fresh water in Sweden and Denmark. Linnceus. 

 About Berlin. Martini. 



It appears to me, that what has been called H. fragilis by 

 English authors, is certainly not distinct from //. stagnalis ; 

 but the shell figured by Martini and Schroeter has a dif- 

 ferent appearance, and may possibly belong to another 

 species ; it tapers more regularly from the base, and the 

 body-whirl is less, though the smaller whirls are more dis- 

 tended than in the shell which Montagu has figured ; the 

 aperture also is more oblong, and not so wide in proportion 

 to the length. Linnaeus says it is so brittle, that it will 

 hardly bear to be touched ; but Bruguiere, notwithstanding, 

 suspects that it is a variety of II. pahtstris. 



PALUSTRis. 170. Shell oblong-acuminated, brown, 

 with the whirls striated and slightly convex ; 

 aperture ovate. 



Helix palustris. Gmelin, p. 3658. Montagu Test. p. 373. 



t. 16. f. 10. Maton and Racket, in Lin. Trans, viii. 



p. 216. t. 5. f. 8. Dorset Cat. p. 55. t. 18. f. 18. 

 Helix stagnalis, Var. Pennant Zool. iv. p. 138, t. 86. 



f. 136 B. Chemnitz, ix. part 2. p. 170. t. V35. f. 1239 



and 1240. 

 Helix fjagilis. Donovan, v. 1. 175. f. 1. 

 Helix fontinalis. Donovan, v. 1. 175. f. 2. 

 Helix, No. 101. Schroeter Einl. ii. p. 205. 

 Buccinum palustre. Midler Verm. ii. p. 131. Schroeter 



Fluss. p. 308. t. 7. f. 9 to 11. 

 Buliraus palustris. Bruguiere Enc. Meth. p. 303. 



