1907.] 



OF CERTAIN SPECIES OF SQUAMATA. 



61 



eparterial bronchus in Heloderma. The length of the bronchi 

 and the complicated structure of the lungs themselves have, 

 however, been remarked upon, and in these matters Heloderma 

 also agrees with Varamis. The figure (text-fig. 16) shows the 

 commencement of the lungs in Heloderma susj)ect'a'in as seen 

 from the dorsal aspect. The long headward prolongation of 

 each lung, not perhaps sufficiently emphasised in Dr. Shufeldt's 

 figure of these organs, is very reminiscent of Varanus. The 

 rings of the trachea are, as correctly stated by Shufeldt, in- 

 complete in the dorsal median line. The bronchi are described 

 by the same writer as " unusually long " ; but it is not clear from 



Text-fig. 16. 



,^r V 



A portion of the trachea, the bronchi, and the upper parts of the lungs of 

 Heloderma, from the dorsal side. 



The left lung cut open to show the course of the bronchus within it. 



the description given, as Prof. Stewart * has pointed out, that this 

 great length does not apply to the intrapulmonary portion of 

 the bronchus. My own measurements of the length of the 

 bronchus up to the place at which it entei's the lung agree with 

 those of Prof. Stewart in the case of Heloderma horridum. I 

 find this length, in fact, to be as nearly as possible 13 mm. To 

 be absolutely exact is impossible, on account of the pliability of 

 the bronchial rings and intersj)aces. The bronchi of Heloderma 

 are therefore shorter than those of Varamts (text-figs. 18 & 19, 



* P. Z. S. 1891, p. 120. 



