1869. } ON THE LAND-SHELLS OF THE SEYCHELLES. 61 
The animal of Me/ampus parvulus (Nutt.) agrees with the above 
in all respects. excepting its tentacles, which are shorter and more 
stout in proportion. 
I will take this opportunity of correcting an error in the habitat 
of Melampus pusillus (Gm.). It does not occur at the Sandwich 
Islands. 
The above observations show that Dr. Gray’s opinion, that the 
shells are not always a guide to the generic relations of the animal, 
is correct. 
2. Additional Notes on the Land-Shells of the Seychelles 
Islands. By Grorrrey Nevitt, C.M.Z.S,. 
The land-shells of the Seychelles are not only remarkably few in 
number, but are also, generally speaking, local. This probably 
arises from the nearly complete destruction at some period or an- 
other of the original flora; for at Mahé, and at most of the other 
islands we visited, it was only on the extreme summit of one of the 
highest passes in the former, and on the top of the mountain at 
Silhouette, that I could perceive anything like a peculiar or ancient 
flora. Praslin, it is true, has a vast number of the Coco-de-mer trees 
and many shrubs, some of which may possibly prove peculiar and 
of interest to the botanist ; but vegetation seems to thrive little better 
under them than under the ordinary Cocoa-nut or Vacoa Palm. It 
seemed to me evident that the flora at Mahé must originally have 
been very different. Large fires haye probably been the chief cause 
of the destruction; and the cutting down the timber, whether for 
firewood or to plant Cocoa-nuts, must also have had considerable effect, 
and have enabled the Pine-apple, Cinnamon, Bamboo, &c., and even 
possibly some of the common Mauritian ferns (Gleichenia &c.) to 
obtain a firm footing. These introduced plants now cover large 
tracts of country, killig all the more delicate indigenous flowers 
and ferns. The first mentioned, more especially, is abundant in most 
of the islands, and grows almost up to the tops of the highest moun- 
tains. Where the large timber has been thus destroyed, the water, 
almost as soon as it falls, forms for itself channels, and, running off 
from the soil, causes it in a short time to become dry and more or 
less arid. This is clearly perceptible both at Mauritius and Bour- 
bon. In such situations there are no shells to be found, excepting, 
indeed, some two or three species, such as Achatina fulica &e. 
By searching, however, where the trees have been recently cut down, 
one finds quantities of dead shells, evidently killed by want of 
moisture and by exposure to the tropical sun. 
Out of the meagre list of the land-shells I found at the Seychelles, 
I believe a considerable number to have been introduced. It does 
not appear difficult to account for this whén one considers that such 
has been the case with a large number of the commonest trees and 
