89 
One characteristic habit, separating the whole of these species, as 
far as I can ascertain, from Melania, is that they are constantly found 
adhering to stones, or the submerged roots of trees and stems of 
aquatic plants, which the Melanie never are ; neither do they burrow 
in sand, as do the Melanie, though they often resort to a sandy loca- 
lity, perhaps for the purpose of breeding. The habit in Ph. sulca- 
tus of crawling several feet out of the water on the damp grass is re- 
markable. 
A few remarks on the various species in detail may prove not un- 
acceptable. 
PALUDOMUS CHILINOIDES, Reeve. 
This is the commonest species of the whole tribe. It is found in 
gently-running water generally, but often in paddy fields and other 
marshy grounds to which these running waters have access. 
The animal is blackish-mottled, forehead produced into an obtuse 
point, slightly indented in the centre and fringed with red dots; 
tentacula two, acuminate; eyes two, sessile, situated about one-fifth 
of the distance up the tentacles. 
I have taken the operculum of this species as the type of the 
family ; it therefore needs no description. 
PaLupomus Lzvis, Layard. 
Shell oblong-ovate ; axis 11 lines, diam. 7 lines; spire acute, ex- 
serted, moderately long; whorls rounded, not depressed round the 
upper part, smooth. Colour olive-yellow, the lower whorls seldom 
marked, but the upper always spotted with one or two rows of arrow- 
headed dots; apex bluish; aperture white. 
Operculum as in Pal. chilinoides. 
Hab. Ceylon, in slow-running streams on the northern side of the 
mountain zone extending into the flat country beyond Anarajahpoora. 
I also obtained a few in a paddy field in the south of the island, near 
the village of Heneratgodde. Mus. Cuming et Layard. 
I think this may prove to be but a variety of Pal. chilinoides, 
although the experienced eye of Mr. Cuming at once separated it 
from that species. It is found in the same localities, and only differs 
from it in wanting the depression round the upper part of the whorls 
and in the colouring ; the mollusk is similar. 
PaLupomus PALusTRIs, Layard. 
Shell ovate, thin; axis 10 lines, diam. 6 lines; spire exserted, 
long ; whorls rounded, rather flat, spirally closely grooved with mi- 
nute granular striz (visible under the lens), Colour of adult shell * 
a rich yellow spotted with dark brown, the markings frequently run- 
ning into wavy lines; apex bluish; aperture white. 
* In young shells the ground colour is almost hidden by the dark markings, 
= the aperture is found to be spirally marked with thin lines of the same 
colour. 
