384 PROCEEDINGS OF THE SCIENTIFIC ASSOCIATION. 
their backs. "Whenever the smallest abrasion occurred in 
the surface of the shell, a deep hole was the result, thus 
exhibiting the value of the thick epidermis with which 
the shells of Neritines are furnished. These Neritines 
presented in these respects an analogy with the fossil one 
from the miocene of Jamaica, described by me in the 
Journal of the Geological Society (vol. 22.) It has, how- 
ever, a differently shaped aperture, and I think the Domi- 
nican shell is probably JV. punctulata Lam. ■ This Neritine 
is the only fresh-water shell I saw in Dominica. 
On arriving at Prince Rupert’s Ray, I obtained the ser- 
vices of three men to accompany me on my ascent of 
HOrne Diablotin, and WO took provisions for four days. 
The first part of the journey from Prince Rupert’s Bay was 
along a vile road of very slippery clay. I rode until we 
came to a ravine, Only passable on foot. Here the real 
ascent begins. It is a Very steep declivity Of rocks and 
stones covered with trees. This is the side of the spur, 
the top of which, once gained, the climbing is not so rapid, 
but the trees are dwarfed. It was none the less necessary 
that every step Of the way should be hewn with the cutlass. 
We reached the last place where water was likely to be 
had about 3 o’clock, having left the Bay at 11. We now 
built a large ajoupa, which, together with preparation for 
dinner and other arrangements, took us till nearly dark, 
when we dined. My bed was far from comfortable, and 
it was sometime before I could compose myself to sleep, 
and I was thus enabled to observe how remarkably free 
the woods were from noxious insects. No mosquitoes or 
sandflies disturbed us ; and although in the early part of 
the evening a few insects were to be heard, later the 
silence was only broken by the booming croak at intervals 
of the tree-frog. These animals, brown and of small size, 
