1908.] OF SNAKES OF THE GENUS CORALLUS. 157 



aoi'ta ; but these few bifurcate and trifurcate, and from secondary 

 longitudinal connections arise the actual intercostals. This is 

 obviously like Corallus cookii. 



The lungs of Corallus caninus are illustrated in the accom- 

 panying figure (text-fig. 27). It is obvious that they are, 

 ^•enerally speaking, more like those of Corallus cookii than they 

 are like those of the Old- World species Corallus madagascariensis. 

 This is chiefly seen in the short length of the intrapulmonaiy 

 bronchus. There is, however, no tracheal lung. The inter- 

 annular membrane is readily to be distinguished from the tissues 

 of the lung by its white colour and thick appearance. It has no 

 lung-like structure ; there is no appearance of alveoli. It is, 

 therefore, fairly sharply marked off from the lung-tissue with 

 which it is continuous. The bronchus of the larger lung descends 

 into that lung for a distance of about 14 mm. This distance is, 

 it Avill be observed, much the same as that found in the case 

 of Corallus cookii. In the smaller lung the intrapulmonary 

 -bronchus is only 6 mm. long. In the case of the larger lung I 

 counted 15 bronchial semi-rings. This, again, is about the 

 number found in Corallus cookii. It is possible that here, as in 

 Corallus cookii, there is some variability in the structure of the 

 lung. But as I have only one example, I can merely point out 

 that it agrees with one set of specimens of Corallus cookii. The 

 intrapulmonary bronchus is rather broad ; it was 8 or 9 mm. 

 across in the case of the larger lung a little way down, and the 

 intervening pulmonary tissue only 6 mm. across. It is important 

 to notice that no trace of a seam could be detected. The intra- 

 pulmonary bronchus of this snake does not, as will be apparent 

 from the figure referred to (text-fig. 27), form a regular gutter 

 with a series of regular and similar annuli. On the contrary, 

 the annuli are very irregular after the commencent, and are fused 

 together and sometimes incomplete. They were to be distin- 

 guished by their very red colour in the example dissected. This 

 irregularity is much more mai-ked than in Corallus cookii. In 

 describing above the lung of Eryx * I have drawn attention to 

 the series of orifices into lung-cells ranged along the sides of the 

 bronchus and between the annuli. In the present species this 

 condition is much more mai-ked, and serves to distinguish the 

 species from Corallus cookii. As will be seen in the figure, these 

 orifices are numerous and scattered irregularly between various 

 annuli. The differentiation between lung and intrapulmonary 

 bronchus is therefore less marked in this species than in many 

 snakes, and is by no means typically Ophidian. It recalls, in 

 fact, very distinctly the lungs of such a reptile as Heloderma f. 



There is a final point in the structure of the lungs of this 

 serpent which demands attention, though it does not bear upon 

 the main object of the present communication to the Society, viz., 

 the relationship of the Neotropical to the Madagascar species of 



* Supra, p. 137. 



t See Beddard, P. Z. S. 1907, p. 61, text-fig. 16. 



