1907.] OF CERTAIN SPECIES OF SQUAMATA. 43 



general appearance. This peculiarity at once divides the two 

 species mentioned from the rest, and other anatomical peculiarities 

 described in the present communication tend to show the sepa- 

 rateness of these two Chamseleons from others. 



It may be remarked that the table of external characters used 

 by Boulenger in the discrimination of the species of the genus 

 brings together Gli. puonilus and Ch. tceniohronchus ^ . 



Pancreas. — The shape of this organ shows differences in the 

 species of Chamceleon which I have examined. In all it lies 

 partly between the stomach and the reciu-rent loop of the duo- 

 denum, and partly dorsal of the stomach and to the posterior side 

 of that organ. That is to say, when the reptile is dissected and 

 viewed in the ordinary position lying on the right side part of the 

 pancreas, that lying between the stomach and the duodenum is 

 visible and the rest is seen when the stomach is raised. The main 

 differences in form are the relative thickness of the gland and the 

 relations of the splenic lobe, which here, as in other Lizards, is to 

 be distinguished at least to some extent from the rest of the gland. 

 The distinction between the two lobes of the pancreas is most 

 plainly to be observed in Gh. dilejns, where the splenic lobe is 

 quite at right angles with the )'est of the gland, and the duodenal 

 part is continued on for a very short distance before it gives off 

 the splenic lobe. In all the remaining species there is no such 

 marked distinction, the two lobes forming one curved elongated 

 mass. This is particularly plain in Gh. iceniohronchus, where the 

 coils of the intestine lie entirely behind the pylorus, and the 

 pancreas is therefore exposed for its whole length and not partially 

 hidden by the stomach. I shall recur later to the coiling of the 

 intestine in this and other species of Ghamceleon. 



The bulk of the gland differs greatly in the sevei'al species. 

 In some it is much thinner than in others, and therefoi'e, as the 

 length is not far from being the same, relatively as to the size of 

 the species the actual bulk fluctuates. Two extremes are well seen 

 in the two species Gh, dilepis and Gh. calcarifer, which, on account 

 of their practically identical size, show the facts very plainly. In 

 Gh. dilepis the gland is very thick, quite as thick as the diameter of 

 the adjacent pyloiic region of the stomach ; its greatest diameter 

 is about 6 mm. On the other hand, in Gh. calcarifer the pancreas 

 is comparatively quite excessively slender, and only measures 

 3 mm. or so in transverse diameter in the region which lies 

 ventrally and in fi'ont of the stomach. There are similar differences 

 between other species ; but I do not give details, as the indi- 

 vidual species vary so much in size that a comparison of the glands 

 would involve rather complex measurements ; these would be of 

 more value if the number of individuals examined were large. 

 The pi'ominent and easily recognisa,ble differences between the 

 two species selected will serve as an example of what also occurs 

 elsewhere in the genus. There are, however, too great a series of 



* Cat. Lizards Brit. Mus. vol. iii. 1887, p. 440. 



