1863. | Notes on the Indian terrestrial Gasteropoda. 361 
_ having pretensions to absolute accuracy, as to the actual number of 
species described up to date. Some shells too, regarded by me as 
mere varieties, are by some esteemed species, so that if the latter view 
prove correct, a reduction would be effected in the number of vagrant 
species e. 9. Helix bistrialis (H. Ceylanica,) and all additions will pro- 
bably go to swell the numbers of species possessing a restricted area, 
rather than those of more extended distribution, so that the numbers 
given above are I think sufficiently correct, and the data ample 
enough as they stand,to support the proposition which I wish to 
establish, viz., that species which from their wide diffusion may be 
termed “ migratory,’ are more aptly described as “ sporadic” and that 
so far from the fact of their wide distribution being the result of a 
general law, or of certain universal conditions favourable to their dis- 
persion, it is plainly an exception, and moreover, so very exceptional 
as to militate strongly against the idea of any law or conditions favour- 
able to migration, ever having existed,so far as we may judge by results. 
The following species are excluded from my list. 
Helix pullula, B. MSS., H. acris, B. 
. bombax, B. Streptaxis Petiti, Gould. juv. 
. ceryx, B. 
. Ceylanica, Pfr. 
. puteolus, B. 
Leptopoma aspirans, B. juv. 
. bistrialis, Beck. 
. clathratula, Pfr. 
. trifasciata, Ch. 
. strigella, Drap. 
. Laidlayana, 2, 
. Bactriana, Hutton. 
. unicincta, B. . propinqua, Pfr. 
. petrosa, Hutton. . vitrinoides, Desh. 
. Zoroaster, Theobald, 
Bulimus Andamanensis, Zh. - 
. Jerdoni, B. 
. rivicola, B. 
THORS eae 
GeEeeeee 
. similaris, Fer. 
Spiraxis Haughtoni, B. 
B. Abyssinicus, Rup. 
B. arcuatus, Hutton. 
. pullus, Gray. B. insularis, Hhr. 
. atricallosus, Gould. B. perversus, L. 
. citrinus, Reeve. B. perversus, L. 
. latebricola, B. 
. tutulus, B. 
Achatina frumentum, Reeve. 
Achatina latebricola, B. sp. 
Botte 
Pupa tutula, B. sp. 
A. gemma, B. 
A. punctogallana, Pfr. 
A. Perrotteti, Pfr. 
24% 2 
A. ceylanica, Reeve. 
A. Nilagirica, 8. 
eee Tey) Wee Ne Te 0 tk | 
