APPENDIX. 



Ill 



particular notice. To determine a snake, it is necessary first to 

 bejome familiar with the shields which cover the head which 

 the study of the figure here given of a snake's head will effect. 



fP ao 



The first shield is the rostral, r. Behind it comes a pair of an- 

 terior or prcefrontals, af, followed by another pair of postfrontals, 

 pf. Behind the postfrontals comes the vertical, v, followed by a pair 

 of OGcipitals, o, and below the occipitals come in the temporals, t. 

 The shield or shields surrounding the nostrils are the nasals, n ; 

 and behind the nasals, the loreal, I. In front of the eye comes 

 the prceocular, o ; above it, the superciliary ; and behind it the 

 postocular, p o, whilst along the lip come in the upper labials, 

 ul. The mandible or lower jaw is covered by the mental, m ; 

 in front, and by the lower labials, II; behind, and behind the 

 mental, follow the chin shields. The belly scales are termed 

 ventrals, or abdominals, the one in front of the vent, the 

 anal ; and those beneath the tail, caudals, or subcaudals. 



On a snake being brought in, the first point to ascertain is 

 whether or no it has a loreal shield, for the rule is absolute, 

 and without exception, that every snake possessing a loreal 

 shield is harmless. If no loreal shield is present, a very brief 

 inspection will show if it belongs to the Hydrophidse with a 



