Annals of the Transvaal Museum, 
185 
or two or start a month or so earlier. The western parts of the island 
are undoubtedly the hottest, and the south-western, as has been pointed 
out, the driest. 
As to vegetation, the south-west is clothed by a low thorn or scrub 
forest of deciduous trees mostly. Conspicuous plants are species of 
Euphorbia (Hintisy section), Asclepiads (chiefly lianes), the Tamarind, 
the little fan-palm Hyphaene coriacea, a species of Adansonia, Sclerocarya 
caffra, and numerous thorn- trees or rather bushes. Orchids, grasses, 
and ferns are rare. In parts the tall thorny stems of species of Sapindaceae 
(Didiera and Alluaudra) give to the landscape a bizarre appearance.* 
A great extent of the south-west is characterized by a calcarous massil 
of Eocene marine deposits in the form of a plateau ; further inland and 
to the east, crystalline schists and granites appear ; extensive marine 
deposits of Cretaceous to upper Permian age have been signalized as 
constituting the rocks of the western parts of the island ; this belt is invaded 
by granite in places, the most important interruption occurring in the 
district of Ambongo, which lies somewhat to the south of Mojunga. On 
the other hand, the plateau and the east is composed mainly of Archean 
rocks, granites, gneiss, and here and there crystalline schists. Near the 
east coast Cretaceous deposits have been found in small areas. Pleistocene 
and recent alluvial deposits occur along the coast in all parts of Madagascar 
and here and there on the plateau ; in the west they are in places very 
extensive. 
This general description, brief as it is, will it is hoped give the reader 
an idea as to the conditions in which the Reptiles recorded in this paper 
live. As may be supposed, though some of the Malagasy Reptiles occur 
throughout the island, others were found to have a limited distribution, 
regulated presumably by climatic conditions. Thus- Hemidactylus mabuia 
is found in all parts of the island except in the higher parts oLthe plateau. 
Mabuia gravenhorsti is ubiquitous. On the other hand, Uroplates fimbriatus 
is confined to the rain-forests of the east ; Homopholis heterolepis to the 
dry south-west. 
List of the Reptiles collected, t 
LACERTILIA. 
Geckonidae. 
Phyllodactylus brevipes, Mocquard. A single specimen from 
Tsivanoa in the south-west. 4025. 
P. bastardi, Mocq. A good many specimens, adult and juvenile, 
were taken at Andranolaho in the fringing forest of the Onilahy River. 
In young specimens the dark markings on the back are much more distinct 
than in adults. 4000-4012. 4057. 
P. porocaster, Boulenger. A single specimen which appears to 
belong to this species from Tsivanoa. Our specimen does not show the 
* We are indebted to Monsieur Perrier de la Bathie for much of the information con- 
tained in this paragraph, and also for the excellent photograph from which Fig. 2, Plate VII, 
has been, prepared. 
f After every species is given the catalogue number in Transvaal Museum collection only. 
