. The life-history of British lizards and their local distribution in the British Isles. rt of the headbehind the frontal is the parietal region. The twolargest shields here, one on either side of the middleline, are the parietal shields (p.). Sometimes theseparietals are in contact with the posterior border ofthe frontal, in other cases—as represented in thediagram—they are separated from the frontal bysmaller shields, which are therefore termed the fronto-parietal shields. Further, if the two parietal shieldsare themselves separated from each other by a shieldin the middle line, this will na
. The life-history of British lizards and their local distribution in the British Isles. rt of the headbehind the frontal is the parietal region. The twolargest shields here, one on either side of the middleline, are the parietal shields (p.). Sometimes theseparietals are in contact with the posterior border ofthe frontal, in other cases—as represented in thediagram—they are separated from the frontal bysmaller shields, which are therefore termed the fronto-parietal shields. Further, if the two parietal shieldsare themselves separated from each other by a shieldin the middle line, this will naturally be called theinter-parietal shield (iP.). Directly behind the pari-etal shields is a smaller one, which is the occipitalshield (o.); while more to the side of the parietalsbut still posterior, are the temporal shields (t.). We have thus disposed of the shields in front ofand behind the large central frontal shield ; thereremains still the large shield found on either side ofthe frontal, which since it lies immediately above theeye region, is termed the supra-ocular (so.).. TYPICAL lizards HEAD : DORSAL ASPECT. {Facing-/>. 86. SPECIFIC CHARACTERS OF BRITISH LIZARDS 87 Lastly, from this aspect, some smaller shields willbe found towards the front end of the snout. Ifany separate the nasal shields from each other theyare called the inter-nasal, and those just behind thenasals may be described as fronto-nasal (fn.) sincethey are placed in the region between the frontaland nasal shields. The single shield at the veryfront of the snout is called the rostral (r.) or beakshield; it is more prominent from above in somespecies than in others. This completes the terminology of the shields of thevertex, and though the names at first sight appearsomewhat formidable, they are so descriptive that acareful study of the arrangement as shown in thediagram will make the matter quite clear. It remainsto describe the shields on the other two surfaces of thehead in a similar manner. 2.
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