96 MALACOZOA. GASTEROPODA. PULMOBRANCHIATA. 



ish-grey beneath, granulated with dusky on the sides above ; 

 the neck and head corrugated, dull-green, the collar green- 

 ish-grey ; the mantle grey, covered all over with small dots 

 of black ; the hind part of the body black, marbled with bluish- 

 grey ; until emptied, the shell appears greenish-black. 



" Auctores hanc cognomine amphibmm dixere, minus vero 

 accurate ; maximam enim vitae partem in sicco vivit, et in 

 aqua non perire pluribus commune est. Sponte in aquam de- 

 scendere nunquam vidi, et e contra quoties eum aqua immisi, 

 confestim egrediebatur. Characteribus quoque terrestrium non 

 dubiis, licet omnes (claris. Schroter excepto) eum fluviatilibus 

 annumeraverunt, instruitur ; tentacula quatuor distincta (Lis- 

 ter ei duo perperam tribuit) ac oculos apice majorum habet, 

 aperturamque testae spuma membranacea claudit. Putris 

 dicitur, quia limo obducta, quod pluribus commune est, in- 

 terdum reperietur, saepius tamen testa lasvis est, verme etiam 

 foeta, nitida, pura. " Muller. 



Abundant among the herbage, in marshy places, and on 

 the banks of streams and pools ; among sedges and Iris 

 Pseudacorus on the coast of Kineardineshire, near Stonehaven ; 

 among sedges and grasses on the margins of the Don, near 

 Seaton ; also by the Inverury Canal. Individuals vary consi- 

 derably in form in the width of the mouth, in the thickness 

 of the shell, and in its striae or rugae. Yet it appears to me 

 that the variations which this species presents are not nearly so 

 great as those of Limnaeus pereger; and that if certain of these 

 variations are to be considered as specific in the one case, so 

 ought certain of those, still more remarkable, to be so viewed 

 in the other. As described above, Succinea putris is of rarer 

 occurrence with us than another variety, the form which it 

 more usually presents being that to which the name of graci- 

 lis has been given by Mr. Alder. Whether this be a really 

 distinct species or not, I cannot affirm, as it sometimes 

 occurs along with the other, and often by itself. It is always 

 of smaller size, with the shell generally thicker, of a duller 

 colour, and frequently in part somewhat opaque. 



Helix succinea. Muller, Verm. Terrestr. et Aquat. ii. 97. 

 Helix putris. Linn. Syst. Nat. i. 1249. Helix putris. Mont. 

 Test. Brit. 376. PI. 16. f. 14. Succinea amphibia. Drap. Moll. 

 Terr, et Fluv. PI. 3. f. 22, 23. Succinea putris. Flem. Brit. 

 Anim. 267. Succinea amphibia. Lamk. Syst. vi. 135 ; Ed. 2. 

 viii. 316. Succinea putris. Gray's Turton, 178. 

 A. S. putris grdcilis. Slender Amber-Snail. 



Shell ovato-oblong, very thin, transparent, glossy, striated, 



