Waite — Review of Australian Typhlopidae 3 



tion : it is usually inoliiicil lowanls the t^round and its function is to assist in the 

 prog-ression of the snal<e when burruwint;. In certain examples of some species, 

 notably T. polyiiyaiuiuicus. there is a dark Ijrown or black blotch on each side of 

 the short tail near the \ent. Seeing that the eyes are almost indistinguishable and 

 the dark blotches often conspicuous, the tails of these snakes are often mistaken 

 for their heads, whilst some ])eople believe that blind snakes have a head at each 

 end: ihmble-headed snakes are occasionally pr(xluced. but such a condition is 

 quite analagous to that of the more familiar doul)le-headed calf. 



Scales. The scales ii\-erlai) and are 

 closely adpressed. broader than long, sub- 

 equal in size and highly polished, so that 

 little resistance is offered in the passage of 

 the snake through tlie soil. There are no 

 ventral plates, as with the majority of 

 snakes, the scales on the belly being indis- 

 tinguishable from those elsewhere : the 



rows of bod_\- scales are so uniformly dis- Fij<, l. Tail and hinder portion of body of 

 pused that their number, normally in an T. polynrammicus. 



even series. i)ro\ides a reliable diagnostic character. ( )wing to their small 

 size and highly-polished surface it is sometimes difficult to count in 

 how many rows the scales are disposed: the process is facilitated liy sticking into 

 the body at different parts of the circumference two or ])erhaps three small 

 entomological pins and counting from pin to pin. when the body may be rotated 

 to include the next pin. .\ watchmaker's glass used in the eye not only enlarges 

 the apparent size of the scales, but allows both hands free for turning the body 

 of the snake. 



Head. The diameter of the head is usually less than that of the body into 

 which it emerges without definite constricti(jn or neck : it is co\ered with enlarged 

 plates, arranged in definite and regular (jrder. l)ut their shape and relative size 

 mav differ in the \arious species, in the determination of which their conforma- 

 tion is utilized. 



The arrangement of the head shields diff'ers from that found in the majority 

 of snakes, inasmuch as no two scales form a suture on the mid line, either above 

 or below. The following illustration shows the general arrangement of the 

 shields, and the names liy which they are known. 



The eyes are rudimentary, but show with greater or less clearness through 

 the ocular scales: it is probable that the visual sensations of the blind snakes are 

 little more than a percejition of the difference Ijetween darkness and light (the 

 name Tyjphlops is from ti'c^Ao? blind, wi// eye). The mouth is small, crescent- 



