476 Zoological Society. 



" At a first glance this Chameleon might be confounded with Cham. 

 Senegalensis, or with Cham, dilepas ; the grainlike scales of the body 

 and the general contour of the head and body being much alike in 

 each. When, however, we come to examine more closely, we shall 

 find sufficient reason to regard it as entirely distinct. Both in 

 Cham. Senegalensis and its immediate ally (if it be truly a separate 

 species), Cham, dilepas, the dorsal ridge and also the median line of 

 the throat and abdomen are strongly denticulate. In this, however, 

 neither the dorsal ridge, nor the abdominal or gular median line, 

 present any such character. In Cham. Senegalensis the tail is re- 

 markably stout at the base, the skin behind the knee-joint is close, 

 and there is a sort of heel, or angular projection (at least in the 

 specimens before me), at the posterior junction of the two portions 

 of the hind-foot. In the Chameleon which I regard as undescribed 

 the tail is slender at the base and long, the skin behind the knee- 

 joint is loose and fanlike, and there is no angular projection or heel. 

 The granulations of the body, it may also be observed, are much 

 less acutely elevated (being smaller and rounder) than in Cham. 

 Senegalensis. 



" The casque between the eyes is comparatively narrower, being 

 there contracted ; it is broader and more rounded however posteriorly, 

 and is less produced. The middle line or keel is a little more dis- 

 tinct ; and between the eyes the casque is more deeply and abruptly 

 concave ; a very small flap or ear, which indeed might easily be over- 

 looked, is produced from the posterior part of the casque, and lies on 

 each side of the neck, as in Cham, dilepas; but as we have said, in 

 this species the dorsal ridge and the median line of the throat and 

 belly are strongly denticulate, or as Daudin said of its ally the 

 Cham. Senegalensis, ' denteles en scie.' 



"Regarding then this species as hitherto undescribed, I propose for 

 it the name of Chamceleon Bibroni, as a tribute of respect to M. Bibron, 

 of the Musee d'Histoire Naturelle of Paris. 



" The characters of Cham. Bibroni may be summed up as follow : 

 Casque (or upper surface of the skull) flat, with a very slight occi- 

 pital keel ; contracted and concave between the eyes, rounded pos- 

 teriorly : superciliary ridge very little elevated, and becoming obso- 

 lete over the nostrils ; a small flap on each side from the posterior 

 edge of the casque lies on the neck ; the dorsal ridge and median 

 line, both of the throat and belly, destitute of a denticulated crest. 

 The grains of the body and limbs small and close-set, those of the 

 casque flat and angular. 



Chameleon Bibroni. Galea plana ; vix apvd occiput carinatd; 



