OF NORTHUMRERLAND AND DURHAM. 127 
Fam. Heuicrpa, Jeffreys. 
24, VITRINA, Draparnaud. 
1, V. pentucipa, Jill. 
Vitrina pellucida, Gray Turt. Man. 120, t. 3, f. 21. 
Among decayed leaves and under stones in woods, on old walls, 
and on the sea banks; frequent. Abundant in short grass, on 
and near St. Mary’s Island, Hartley ; where, in some states of 
the weather, it is difficult to walk without crushing numbers of 
them. 
25. SUCCINEA, Draparnaud. 
1. S. purris, Linn, 
Suceinea amphibia, Drap. Hist. Moll. 58, t. 3, f. 22, 23. 
Succeinea putris, Gray Turt. Man. 178, t. 6, f. 73. 
Var. Succinea gracilis, Ald. in Newe. N. H. Trans. 11. 338. 
Succinea Pfeifferi, Gray Turt. Man. 179, t. 6, f. 74*. 
On aquatic plants in marshy places, and at the borders of ri- 
vulets, common. 
This species is subject to very great variety. Further obser- 
vation inclines us to unite with it the S. gracilis of our former 
Catalogue, though opinions are still very much divided upon that 
point. The S. Pfeiferi of Rossmassler does not appear to be ex- 
actly equivalent to our S. gracilis, though doubtless a nearly 
allied variety. Rossmassler describes it to be thick, and with a 
pearly lustre inside, which is not the case with ours. There isa 
very stunted and dwarf variety with the animal nearly black, 
not uncommon on plants and stones close to the edge of rivulets, 
and frequently on stones surrounded by the stream ; which, if 
S. gracilis be retained as a species, seems entitled to a similar 
rank. 
26. HELIX, Linneus. 
1. H. asprersa, Mull. 
Helix aspersa, Gray Turt. Man. 128, t. 4, f. 35. 
In gardens and on hedge sides, common. Very abundant on 
the sea banks on a limestone soil. 
