86 BRITISH LIZARDS 



These are the' most constant in their presence and 

 arrangement, and are always looked for first. 



The most conspicuous is often the frontal, a large 

 polygonal shield in the centre of the top of the head, 

 a single shield in the middle line, which is easily re- 

 cognised (f.). Immediately in front of this, anteriorly 

 that is, are some smaller shields whose number and 

 arrangement will be found to vary considerably, they 

 are called from their position relative to the frontal, 

 the pre-frontal shields (pf.). The part of the head 

 behind the frontal is the parietal region. The two 

 largest shields here, one on either side of the middle 

 line, are the parietal shields (p.). Sometimes these 

 parietals are in contact with the posterior border of 

 the frontal, in other cases — as represented in the 

 diagram — they are separated from the frontal by 

 smaller shields, which are therefore termed the fronto- 

 parietal shields. Further, if the two parietal shields 

 are themselves separated from each other by a shield 

 in the middle line, this will naturally be called the 

 inter-parietal shield (ip.). Directly behind the pari- 

 etal shields is a smaller one, which is the occipital 

 shield (o.) ; while more to the side of the parietals 

 but still posterior, are the temporal shields (t.). 



We have thus disposed of the shields in front of 

 and behind the large central frontal shield ; there 

 remains still the large shield found on either side of 

 the frontal, which since it lies immediately above the 

 eye region, is termed the supra-ocular (so.). 



