91 
PALUDOMUS SPIRALIS, Reeve, 
I include in this group, from its resemblance to my Pal. palustris. 
The only specimens I ever saw are in Mr. Cuming’s cabinet. 
PALUDOMUS DILATATUS, Reeve. 
Operculum concentric ; nucleus subcentral, dextral. 
Hab. Ceylon, Rambodde Pass, mountain torrent. This species was 
given to me along with Pal. globulosus ; I therefore know nothing of 
its habits. 
Genus Tanai, Gray. 
TANALIA LORICATA, Reeve. 
This species grows to its largest size in the Calloo ganga, above 
Ratnapoora, where it is found in the most rapid foaming currents ad- 
hering to rocks. It resorts to deep sandy pools and reaches at some 
seasons, but apparently will not exist in a river devoid of rocks and 
rapids. Most of the streams of the southern provinces answering to 
this description contain it; but I never met with it to the northward, 
where the rivers become more sluggish. 
The mollusk is almost black. 
TANALIA CRINASCENS, Reeve. 
TI doubt this being more than a geographical variety of the preceding 
species ; and not being aware that it had been separated from it, did 
not pay attention to the operculum, though it evidently belongs to 
this group. I have only received the species from one locality, 
Kadaganava Pass, between Colombo and Kandy ; but have interme- 
diate varieties, on which half the spines are solid, as in loricata, 
half capped and hollow, as in crinascens. 
T. area, Reeve. T. Layarpt, R. T. unpaTA, R. 
I seek in vain for sufficient distinction in these species to separate 
them from loricata. Take a strongly-marked specimen of each, and 
the division appears an excellent one; place a hundred of each, and 
the gradations are imperceptible. 
As far as my recollection serves me, there is nothing different in 
the animals ; but as I was not aware of the separation of erea and 
Layardi, 1 did not closely scrutinize them; however, of undata 
dozens passed in review with careful survey. 
They are found with loricata and the pseudo-variety crinascens 
before mentioned ; and the opercula are undistinguishable, save that 
those of @rea having a wider aperture to fill, are larger and not 
quite so angular. I look upon them as varieties of loricata. 
TANALIA GARDNERI, Reeve. 
Operculum not distinguishable, except in size, from that of lori- 
cata. In very large specimens the angle is often very great, and is 
bent outward on the exterior side. 
Hab. I found this species in a waterfall pool at Tambillichna, 
below Ratnapoora ; also in the Calloo ganga, but only in the most 
rapid current, mixed with Joricata and the next species. 
