LIZARDS. 71 
types into a creature of an essentially forbidding and threatening aspect. The 
membranous frill, previously applied closely to the neck, is suddenly, and syn- 
chronously with the opening of the mouth to its fullest width, erected in such 
manner that it stands out at right angles around the animal’s head. The dimen- 
sions of this frill in adult individuals may be as much as from eight to ten inches in 
diameter and in its erected condition the lizard’s body, when facing the observer, 
is almost, if not entirely, concealed from view. A fairly correct presentment of the 
Frilled Lizard thus aroused to anger or standing defiantly at bay is embodied in the 
two photographs from life reproduced as the heading to this Chapter. The ferocious 
appearance of Chlamydosaurus here depicted only in monochrome is materially 
enhanced in the living subject by the glowing tints of vermilion red, yellow, and 
steel blue that suffuse that portion of the frill which covers the front of the neck 
and chest, combined with the bright yellow distinctive of the tongue and the lining 
membrane of the mouth and throat. The dashes and pencillings of rosy red which 
accentuate the outlines of the upper and lower jaws and the margin of the singular 
ciliated irides, also add sensibly to the creature’s angry aspect. 
With the assistance of the talented natural history artist, Mr. F. W. Frohawk, 
the author has succeeded in obtaining a highly characteristic portrait of the example 
which he recently brought alive to England, with which has been incorporated the 
colours, copied from life, of one of the brighter male examples immediately after 
its capture in Roebuck Bay. This portrait appeared originally as a black and white 
drawing in the pages of the “Field” for August 3rd, 1895, and subsequently with the 
colours, as added by the author, in conjunction with a paper descriptive of the animal 
contributed to the “Proceedings of the Zoological Society” for the same year. The 
author’s obligations to the “Field” Newspaper and the Council of the Zoological 
Society for permission to reproduce the illustration in these pages may be here most 
appropriately recorded. 
With regard to the significance and utility of the erectile frill in Chlamydosaurus, 
the fact that this organ is of insignificant proportions in young examples, and attains 
its full development only in adult individuals, would appear to indicate that, as a 
structure, it has been developed within comparatively recent times and does not 
represent the residual heritage of a remote ancestry. Respecting its function, there 
can be but little doubt that it fulfils simply the réle of a “scare-organ,” where- 
with it terrifies, and diverts the projected attack of, many ordinary enemies. 
Instances have, in fact, been related to the author of dogs which will readily rush 
