SUCCINEA. 57 



S. PUTRis. Lirmceus. PL VII, fig. 18. 



Oblong, reddish amber colour, spire consisting of three whorls, 

 email ; aperture oblique. 



Helix putris, Mont. Succinea amphibia, Drap. 

 Succinea gracilis. Brown, 8fc. 



Naturalists have found some difficulty in describing 

 and affording limits to the species under this genus, 

 especially in regard to this particular member. It com- 

 prises, under the present arrangement, two distinct 

 species of Gray, S. putris and Pfeifferi, as it is con- 

 sidered that the localities in which they are found, have 

 sufficient influence on their nature to account for the 

 difference between them. The shell of the normal form 

 is large, sometimes attaining three quarters of an inch 

 in length ; the colour varies from a rufous amber to a 

 pale yellow. The surface is glossy and more or less 

 wrinkled. Animal grey, spotted ; tentacles rugose. 

 On account of the diversities of form, &c., which this 

 shell assumes, is has been split up into many varieties. 



vm\ AMPHIBIA is more compressed, and has the 

 sutures more oblique. The whorls, scarcely three in 

 number, are flattened above and rounded below, the 

 apex being very minute. Fine specimens are about 

 half- an -inch in length. 



The other forms are gracilis, oval, more or less 

 swollen, of a more pallid and less rufous colour than 

 the preceding. Its whorls typically much rounded ; 

 its sutures not peculiarly oblique : and its spire never 

 elongated. Intermedia presents the modified peculi- 

 arities of the preceding extreme forms ; there are three 

 and a half coils, so that the spire is occasionally more 

 elongated in proportion than gracilis or ampliiUa. 



Hah. Abundant in almost every locality. S. Putris 

 inhabiting damp woods and meadows, while arnphihia 

 prefers a still damper situation, and is never found 

 except on aquatic plants and mud by the sides of slow 

 running streams, ditches, &c., frequently immersed 

 in the water. 



