410 REPTILIA ORDER III. SQUAMA TA. 



scales on the back. Another South European genus, also extending into the 

 north of Africa, is Psammodromus, the members of which differ from both 

 the genera above-mentioned by the slight development or complete absence 

 of a collar or gorget round the throat. 



A small neatly-made lizard, commonly known as the skink (Scincus offici- 

 nalis), which inhabits the Sahara desert and the countries bordering the Red 

 Sea, is the type of the last large and important family of tho 

 Slunk Tribe. Lacertilia. It should, however, be mentioned that the 

 Family small African family of the Gerrhosauridce includes iive 

 Scincidce. genera, which, to a certain extent, serve to connect the 

 Lacertidce with the Scincidte. They have, for instance, the 

 scales of the body underlain by bony plates of peculiar internal structure, as 

 is the case with the latter family, whereas in the union of the two premaxil- 

 lary bones and the presence of pores on the thighs, they are like the former. 

 The presence of such bony plates beneath the scales, the distinctness of the 

 two prernaxilUe, and the invariable absence of pores on tho limbs, are 

 characters amply sufficient to differentiate the IScincidce from the Lacertida\ 

 There are twenty-five genera included in the family under- consideration, in 

 one of which (Lygosoma) no less than one hundred and fifty-nine distinct species 

 are recognised by zoologists. With such a number of different forms, it is not 

 surprising to find that the family is cosmopolitan. Its head-quarters are, 

 however, the Australasian and Oriental countries, together with the islands 

 of the Pacific and Africa. Skinks are essentially terrestrial lizards, all loving 

 dry sandy deserts, where many burrow in the soil ; and it is probably largely 

 due to such habits that the lower eyelid is furnished with a transparent 

 window in the centre, so that the eye can be used when protected by its 

 covering. A peculiar feature of the family is to be found in the circumstance 

 that the young are almost invariably born in a living condition. Whereas, 

 in all cases the limbs are relatively short, in certain instances one, and in 

 others both pairs are wanting. Many of the above-mentioned features clearly 

 indicate that they are a highly specialised group. Since the number of young 

 produced at a birth may be as low as two, and does not seem to exceed half 

 a score, the rate of increase of these lizards is comparatively slow. 



The common skink (Scincus officinalis) which isasrnooth-scaled, parti-coloured 

 lizard of about eight inches in length, owes its scientificname to the circumstance 



that its flesh was formerly employed in 

 European medicine, as it still is in the 

 East. It is a creature common enough 

 in Syria and Palestine, where it burrows 

 in the sandy soil. Its flesh is stated by 

 European travellers to be by no means 

 unpalatable if properly cooked. The 

 most extraordinary-looking member of 

 the entire family is the Australian stump- 

 tailed lizard (Trachysaurus rugosus), 

 which is covered with large rough 

 browny scales, underlain by thick bony 

 Fig. 20. COMMON SKINK plates, in such a manner as to give it the 



(Scincus offidnalis). appearance of an extremely elongated pine- 



cone. The short and broad head is triangular in form ; the limbs are very short, 

 the front and hind pair being widely separated from each other ; and the tail is 

 reduced to a very short, wide, rounded stump. In its habits the lizard is slow 



