VERTEBRATA. REPTILIA. 



ORDER III. OPHIDIA.* 



To the Serpent races alone does the term " Rep- 

 tile" strictly apply, as in them there are no external 

 limbs, and, in most, even the last rudiments have 

 disappeared from the skeleton. Their body is great- 

 ly lengthened ; there are three families. 



FAM. I. ANGUINA.f 



AnguiSjthe Slow-worm. 



Notwithstanding their serpentine form, the Slow- 

 worms are more closely allied in structure and habits 

 to the last Order than to the present. They are 

 completely covered with small overlapping scales, 

 possess visible eyelids, have a solid bony head, and 

 the rudiments of limbs in the skeleton. On the 

 other hand, one of the lungs is much less deve- 

 loped than the other. The common Slow-worm or 

 Blind-worm of our own country, (A. Fragilis,} is 

 a good example of the genus. It is about a foot 

 in length, of a silvery brownish hue, with some 

 lines of dots. The general form is nearly cylin- 

 drical, scarcely tapering to the head and tail. It 

 is a gentle, inoffensive creature, rarely attempting to 

 bite even when handled, and if it attempt to do so, 

 the teeth are too feeble to pierce the skin. It is 

 so timid that, on being frightened, it contracts so 

 * "OQis, opJus, a serpent, and iTSos, eidos, likeness, f Anyuis, a snake. 



