116 THE BRITISH REPTILES. 



immovable, and there are no movable eyelids, the lid being a trans- 

 parent scale of the horny epidermis. The head scales are large 

 plates, the ventral scales are transverse shields. There are nine 

 orders, only two of which, Colubridas and Viperidae, are represented 

 in our list. 



In the Colubridas both jaws are toothed ; the mandible has no 

 coronoid ; the maxillary is horizontal, and does not rise at a right 

 angle to the transpalatine ; the quadrate is carried by the supra- 

 temporal, which is loosely attached to the top of the skull. The 

 facial bones are movable. To this order belong nine-tenths of the 

 living snakes. It is divided into three groups, one in which the 

 front maxillary teeth are grooved or perforated, another in which 

 one or more of the hinder maxillary teeth are grooved, another in 

 which all the teeth are solid. In the first the snakes are all 

 poisonous, in the next they are doubtful or slightly poisonous, in the 

 last they are harmless, and to it belong the only two British genera, 

 Tropidonotus and Coronella (Plate xxix., 79, 80). 



In the Viperidae both jaws are toothed, but the only maxillary 

 teeth are the poison fangs and their reserves. The teeth in the 

 mandible are solid ; the fangs are perforated with a hole in front at 

 the base connecting with the poison gland. The mandible has no 

 coronoid ; the maxillary is short and thick, and erectile at a right 

 angle to the transpalatine ; the quadrate is carried by the supra- 

 temporal, which is loosely attached to the top of the skull. The 

 facial bones are movable. All the genera but one are viviparous. 

 The only British genus is Vipera (Plate xxix., 81). 



And now for the seven genera in alphabetical order : 



Anguis. Plate xxviii. LACERTILIA. 



75- fr&gilis, SLOW-WORM. No visible legs; eyes with movable 

 eyelids. 



The Slow-worm, though frequently called the Blindworm, has a 

 particularly bright little eye. The tongue is broad and notched, but 

 not cleft or forked ; the teeth are small and slightly hooked, and are 

 absent from the palate. The body and tail are covered with small 

 rounded scales that look like faint markings, a ring of larger scales 

 dividing off the tail from the body. The body is cylindrical, without 

 a lateral fold, and of much the same diameter throughout. The skin is 

 smooth generally brownish-grey above, with rows of dark spots 

 down the back and along the sides, and bluish-black with white 

 reticulations below and has a metallic lustre which gives the 

 animal the appearance of a short round bar of tarnished copper. 

 In length the Slow-worm may reach seventeen inches, but it does not 

 often exceed twelve, more than half of which is tail. It is not a snake, 

 it is not venomous, it is quite harmless to man, and when caught or 

 alarmed becomes so rigid with fright that some of its tail is 

 frequently broken off, to grow again, but not to the same length as 

 before. It may frequently be noticed basking in the sun, a habit 

 characteristic of the female a week or two before the eggs are 

 brought forth in July, August, or September. The young make their 

 escape from the eggs very soon after they are extruded. There are 



