1871.] F. Stoliczka— Notes on Terrestrial Mollusca. 233 



Ad., imperfecta, Desh, mucronata, Reeve, appear to represent quite 

 a different group of Zonitid^e with almost membranaceous shells. 

 The South Indian H. ampulla probably belongs to this group. The 

 shells are somewhat allied to the new genus Conulema (type fT. 

 attegia, Bens.), but the whorls are fewer and rapidly increasing. 

 Their closest ally will probably be Helicarion, but an examination 

 of the animals is necessary in order to determine the extent of the 

 group. 



I expect that several species of Albers' Thalassia, which chiefly 

 includes Australian shells, will also be referable to Rotula, but I 

 am not quite certain that Semper's Euplecta is sufficiently distinct 

 from the typical forms of Thalassia. 



ROTTTLA ANCEPS, Gould, pi. Xvii, figS. 1 — 3. 



Helix anceps, Gould, 1844, Bost. Journ., IV, p. 454, pi. xxiv, fig. 4; eadem 

 Cliem., Pfeiff., Reeve, &c, ( ? = Nomina arata, Blf.). 



Chemnitz's figure of the species is excellent, but somewhat flat- 

 ter forms also occur. The fresh shell is thin and transparent, 

 covered with a shining epidermis ; the strise of growth are above 

 strongly marked, crossed by fine spiral lines, the base is polished 

 and with hardly traceable strife of growth. 



I found the species common to the south of Moulmein and near 

 Amherst on trees and bushes in damp localities. At Damotha I 

 obtained only four dead specimens on a limestone rock ; they have 

 distinctly a more solid shell, but do not differ in any other respect 

 from those found on trees. 



Typical specimens of Blanford's N. arata from Upper Burma 

 (Proc. Zool. Soc. 1869, p. 448), differ by haviug the base of the 

 last whorl less inflated and somewhat more distinctly striated, but 

 the differences are such, as may easily be referred only to a local 

 variation of anceps, the shell being larger and flatter. 



The animal is dark grey with a distinct greenish tinge, darker 

 on the front part of the head and on the pedicles. Foot long, 

 slightly more than twice the longer diameter of the shell ; lateral 

 line distinct, rather high up above the edge of the sole ; the por- 

 tion of the foot above the line is obliquely furrowed, below it 

 nearly smooth, or very finely striated. Posterior part of foot 



30 



