192 Mr. O. Thomas on 
brought over in the same manner as Planorbis dilatatus and 
Physa heterostropha, 
P. Brownii, Petterd, from Tasmania, more closely resem- 
bles this species than any other with which I am acquainted, 
and it is curious that the other species of Paludestrina 
(P. Jenkinsi), added of recent years to the British fauna, 
should also have an extremely close Tasmanian representative 
in P. Legrandiana of Brazier. 
The present species may be thus described :— 
Paludestrina Taylort. 
Animal with the foot pale beneath, oblong, rounded behind, 
scmewhat auriculate anteriorly, with the front edge straightish 
or even slightly sinuated. Proboscis cleft beneath in front, 
blackish above and at the sides, pale at the end; body also 
blackish at the upper part of the sides. ‘Tentacles moderately 
long, scarcely tapering, rather obtuse at the tips, semitrans- 
parent, with a dark streak on one or both sides; eyes coal- 
black, large, slightly prominent at outer base of tentacles, 
with a sulphur-coloured spot above each. 
Shell subcylindrical, turreted, umbilicated, brownish or 
olive horn-colour, obscured by a blackish earthy deposit ; 
whorls four in number, very convex, separated by a deep 
suture, clean specimens exhibiting fine lines of growth; aper- 
ture broadly ovate, a little narrowed above; peristome con- 
tinuous, outer margin simple, columellar edge slightly 
thickened and faintly reflexed. 
Length 24-3 millim., diam. 14. 
Operculum paucispiral, thin, horny, slightly concave 
exteriorly. 
The sulphur spots above the eyes are a very striking feature 
in this mollusc, and under the microscope have a granular 
and even almost luminous aspect. The small size, besides 
the other characters mentioned, readily distinguish this from 
the other British species. I have much pleasure in associating 
with this form the name of its discoverer. 
XXIV.—New South- American Sciuri, Heteromys, Cavia, 
and Caluromys. By OLDFIELD ‘THOMAS. 
Sciurus griseogena meridensis, subsp. n. 
Precisely similar in size and general colour to the typical 
form, but the fur very much longer (hairs of back about 
