68 
dense tussocks of coarse and spiny vegetation. (Sources summarised 
by Arnold, 1989b). 
Holaspis (Forest regions of tropical Africa and some adjoining 
savanna areas.) 
The single species, H. guentheri, occurs on the trunks and branches 
of standing trees, often at some height, and does not usually come to 
the ground. It appears to spend much more time on steep and vertical 
surfaces than any other lacertid and also often investigates narrow 
crevices in wood and under bark. Holaspis is unique within its 
family in being able to glide from tree to tree. (Sources summarised 
by Arnold, 1989b). 
Gastropholis (Forested areas of tropical Africa) 
The little information available suggests the four species of this 
genus are arboreal and essentially canopy forms, spending much of 
their active time among twiggy vegetation. (Sources summarised by 
Arnold, 1989b). 
Tropidosaura (S Africa). 
These are ground-dwelling species in mountain areas and are usu- 
ally encountered in and around dense grassy or bushy vegetation. 
Such behaviour occurs in the most basal species of the clade, 7. 
montana, and may be primitive for the genus, all members of which 
lack a collar beneath the throat and have large imbricate, pointed, 
keeled dorsals, features usually associated with use of dense vegeta- 
tion as cover (Arnold, 1973). Two of the four species, 7. gularis and 
T. cottrelli, also climb on rock surfaces to a limited extent. If this is 
a derived condition it is likely to have developed twice. (Sources: 
Branch, 1988, pers. comm.; pers. obs.). 
Poromera (Forested areas of W Africa from Gabon to Cameroun.) 
Occurs on the forest floor and on fallen logs (M. Largen pers. 
comm.; Freyhoff, 1994) and also climbs in grassy vegetation (Perret 
and Mertens, 1957). 
Nucras (E and southern Africa) 
Ground dwelling especially in mesic and arid savannah often on 
sandy soils. Many species are secretive and only seen after rain, 
although N. tessellata is active at high temperatures. N. lalandei 
occurs under stones and in long grass. (Sources: Branch, 1988, pers. 
comm.; FitzSimons, 1943; Pianka, 1986). 
Philochortus (NE Africa; isolated localities in and around the Sahara 
desert) 
Ground dwelling in dry places on sandy and stony soils often with 
grass and bushes (R.H.R. Taylor, notes). Matschie (1893) recorded 
P. neumanni from high grass. Philochortus possesses morphological 
features that have independently evolved in the lacertid genera that 
climb in grassy vegetation, Zakydromus and Poromera, and appear to 
confer performance advantage in that situation; these features include, 
enlarged vertebral scales with a coarse microornamentation of 
anastamosing ridges, a long tail and sagittally expanded neural 
spines (Arnold, 1997). 
Latastia (SW Arabia, NE and E Africa, westwards through the 
Sahel) 
Ground dwelling in dry places with sparse vegetation (Dunger, 
1967; R.H.R. Taylor, notes; J. Vindum, pers. comm.). 
Heliobolus East and tropical southern Africa, Sahel etc.) 
Ground dwelling in dry places. H. lugubris occurs on sparsely 
vegetated compacted sandy plains and in bush veldt (Branch, 1988; 
FitzSimons, 1943; R.H.R. Taylor, notes). 
Ichnotropis (Tropical southern Africa) 
Ground dwelling in arid and mesic savannah often with sandy soil 
(Branch, 1988; FitzSimons, 1943). 
E.N. ARNOLD 
Pseuderemias (NE Africa) 
On dry ground ranging from firm, rocky substrata to dunes (Gans & 
Laurent, 1965; R.H.R Taylor, notes). 
Meroles (SW Africa) 
The evolution of this arid ground-dwelling clade is discussed else- 
where (Arnold, 1990, 1991) and habitat differences between the 
species summarised (Arnold, 1995). Most species occur on sandy 
substrata but a succession of shifts to increasingly extreme environ- 
ments occur along the main lineage of the phylogeny. The sequence 
is: relatively firm surfaces (M. knoxii and M. suborbitalis), vegetated 
hummocks separated by open areas of soft sand (M. reticulatus), 
areas of looser sand and more open vegetation (the subgenus Saurites, 
consisting of M. ctenodactylus, M. micropholidota and M. 
cuneirostris), bare slip faces of dunes (M. anchietae). Overall the 
trend is towards softer substrata and more open situations. 
Pedioplanis (S Africa and Namibia) 
Ground dwelling in dry usually open areas on firm substrata such as 
flat and sloping rocky areas, gravel, hard soils, sandy plains and 
grassy hillsides (FitzSimons, 1943, Branch, 1988). 
Eremias (Palaearctic Asia and adjoining regions) 
Ground dwelling in dry situations and habitats occupied by mem- 
bers of the genus include firm soil, firm sand, loess and aeolian sand; 
the latter habitat may have been entered twice (S. C. Anderson, in 
press; Minton, 1966; Shcherbak, 1974; Smith, 1935). 
Acanthodactylus (N Africa, Middle east to NW India) 
Ground dwelling in open dry situations, usually on light soils or 
sand. Within this general environment, there is considerable varia- 
tion in microhabitat among species. Many relatively primitive forms 
usually occur on fairly firm substrata with at least scattered vegeta- 
tion and the A. pardalis group 1s found on loess soils. Perhaps three 
lineages appear to have shifted into aeolian sand habitats, although 
they may sometimes have partially reverted to firmer ground: 1. A. 
grandis of Syria, Iraq and adjoining regions; 2. the A. scutellatus 
clade of North Africa and northern Arabia of which A. longipes is 
found in the softest most open situations (Perez Mellado, 1992; S. 
Baha el Din, pers. comm.); 3. a clade ranging from Arabia to NW 
India consisting of A. cantoris and its immediate relatives, among 
which A. haasi 1s distinctive in often climbing in bushes. (Sources: 
S. C. Anderson, in press; Arnold, 1983, 1984, 1986a; Dunger, 1967; 
Ross, 1989, Mellado & Olmedo, 1991; Perez Mellado, 1992) 
Mesalina (N Africa, Arabia, Middle East to NW India) 
Ground dwelling in dry, open situations on firm substrata. Most 
species tend to occur on compact often sandy soils but members of 
the clade containing M. guttulata and M. watsonana are often found 
in gravelly, stony or rocky situations. (S. C. Anderson, in press; 
Arnold, 1984; Minton, 1966; Perez Mellado, 1992: Ross, 1989). 
Mesalina ercolinii (Lanza and Poggesi, 1975) is only known from 
a single specimen collected in central Somalia. It was initially 
assigned to Eremias but is probably part of the Mesalina clade 
(Arnold, Lanza et al., in press). The sole individual was collected in 
a savannah habitat but there are no direct observations on its life 
mode. 
Ophisops (Coastal regions of N Africa; Turkey and Middle east to 
India and Sri Lanka) 
Ground-dwelling, usually in generally dry situations often on sandy 
soils which may bear grass or patches of dense vegetation. (S. C. 
Anderson, in press; Minton, 1966; Schatti & Gasperetti, 1994; 
Smith, 1935). In Sri Lanka, O. leshchenaultii occurs in more open 
dune areas (T. B. Karunaratne, pers. comm.). 
