1875.] MR. CALDWELL ON THE ZOOLOGY OF RODRIGUEZ. 645 
tailed information from the Naturalist who accompanied the Trausit- 
of-Venus Expedition. 
Geologically, the island is very similar to Mauritius, of basaltic 
origin; but a large portion of the south-western part is composed of 
very ancient upheaved coral, abounding in fissures and caverns large 
and small, a number of which were minutely explored and dug over 
by Mr. H. Slater in the latter end of last year. 
So effectnally had Mr. Slater done his work that though I several 
times visited the large caverns and some smaller fissures, I only 
succeeded in getting two Solitaire-bones, and at last I spent a couple 
of days consecutively in the search and got nothing. The next 
morning, after another ineffectual search, we were returning home to 
camp to breakfast, when Sergeant Morris of the Police Force went 
into a small hole to procure me a few semifossil shells of Helix 
bewsheriana (Morelet, Journal de Conch. 1875, p. 23), and found a 
magnificent tibia. Of course we all entered, and found the hole to be 
the entrance of a small but very well formed cavern of three stories 
formed like steps, none of the chambers being more than 10 feet 
square, and close alongside one of the large caverns in which a mass 
of bones had already been found. How it had been overlooked I 
am at a loss to conjecture. 
We remained till half-past four, digging with hands, nails, and 
pointed sticks in the loose and nearly dry earth; and I obtained the 
remains of at least 37 birds, besides bones of Tortoises, Gulls (of 
several kinds) Bats, &c. &c., and many shells of Gasteropoda. 
It was this same Sergeant Morris who, under the direction of Mr. 
George Jenner, had already procured for Mr. Edward Newton the 
handsome collection of Solitaire-boues on which he and his brother 
prepared the memoir published in the Phil. Trans. for 1869, vol. clix. 
Morris is an enthusiastic naturalist in his way ; and had he, at the 
time when he collected these bones, had the slightest training, I 
have no doubt many perfect specimens would have been obtained, 
by keeping separate the bones which apparently belonged to any 
one bird. 
Out of the number of birds I have mentioned, I got that day a 
skeleton all but complete. I suppose it to be a female, as the fighting 
bones are not largely developed, although the bird is evidently mature. 
On one side there are seven ribs complete ; but I find no trace of the 
articulation of the eighth dorsal rib (see Messrs. Newton’s paper, 
Phil. Trans. vol. clix. 1869, p. 334), though in another specimen there 
is about 2 of an inch of this rib existing on each side. The two pubic 
bones are in very good preservation ; and though, unfortunately, one 
was broken off in taking the bones from the earth, I have been able 
to reunite it perfectly to the pelvis. The posterior extremities of 
these bones in different specimens present most singular variations. 
The pelvis is quite complete on the right side; but the posterior end 
is missing on the left; I am not sure, however, that I did not put it 
away at the time and that it will not be found: the caudal extremity 
is incomplete ; but I found several detached bones, which I have not 
attempted to put in place. 
