1907.] OF CERTAIK SPECIES OF SQUAMATA. 37 



only varies in individuals, but also on the two sides of the body 

 of the same specimen, their mere number and arrangement can 

 hardly be utilised as distinctive of species without examining a 

 large series. Yet I am disposed to think, for reasons that will be 

 discussed later, that Cli. inonaclius does differ from Cli. vulgaris. , 



In Chamceleon calcarifer the lungs show the same general 

 structure as do those of Ch. vidgaris. That is to say, the lung- 

 itself is frayed out into processes posterioi-ly. These again may 

 or may not give rise to the tubular caecal outgrowths. The latter 

 show no network upon their surface, but the direction of the fibres 

 of which they are partly composed is rather circular. On the 

 ventral side also, some way in front of the end of the lung, the 

 lung itself is prolonged into processes. I counted altogether in 

 one lung examined fifteen tubular c?ecal outgrowths. But as the 

 numbers have been stated by Wiedersheim to vary in Ch. vulgaris, 

 the exact number is probably not a matter of importance. They 

 were, however, certainly more numerous than in an example of 

 Ch. vulgaris which I have myself studied. What appears to be 

 of importance is to note that the lung itself is divided and that 

 the tubular outgrowths do not arise from a lung with an entire 

 margin. The subdivisions of the cavity of the lung seem to be 

 exactly as Wiedersheim has described for Ch. vulgaris. In 

 Ch. verrucosii,s the tubulai- ctecal outgrowths are ver}- numerous. 

 I counted twenty-five or more of them. All the cfecal outgrowths 

 were borne in four tufts, of which that furthest from the bronchus 

 was the largest, and consisted also of an outgrowth of the lung 

 itself. The individual tubular cteca were frequently to be seen 

 arising by the division of a common stem (text -fig. 10, p. 38). 

 The disposition of the cteca in this species is very different from 

 that which Thave observed in others. 



The lungs of Chamceleon dil&pis appear to diffei' in certain respects 

 from those of the species that have been hitherto described. The 

 obvious difference is the tubular character of the cfecal outgi-owths, 

 which have hardly any dilated termination, shown so plainly in 

 Ch. parvilohis, for example (text-fig. 12, p. 39). In the second 

 place, the tubular cisca are thick- walled and not at all transparent 

 except in pai-ts, and then not so transparent as in other species. 

 Furthermore, these processes are distinctly shorter in Ch. dilepis 

 than they are in Ch. jxtrvilobus, as is indicated in the annexed figure 

 (text-fig. 11, p. 39). The differences above set forth can hardly be 

 due merely to a different state of contraction, since both specimens 

 came out of the same bottle of alcohol in which they had been 

 preserved some time since ; and very well preserved, for there was 

 no trace of softening or disintegration of the viscera. The cseca 

 of Ch. dilepis are certainly to some extent contracted, as they can 

 be pulled out without using undue force. There remains, liowever, 

 a condition which differs from the attenuated and thin c?eca of 

 Ch. pai'vUobas and Ch. verrucosus on the one hand, and from the 

 prolongation of lung-substance with shorter CBeca in Ch. calcarifer, 

 on the other. The marked distinctness of the cfeca from the Itmg 



