1908.] OF SNAKES OF THE GENUS CORALLUS. 137 



while in another example (a female) by one scale only ; whereas 

 in its close ally, Boa constrictor, I found in one individual three 

 scales on either side of the mental groove. I may take this 

 opportunity of mentioning that I found in three examples of the 

 Boid Eri,ygrus carinatus five or six scales on each side of this 

 groove. The number of scales bordering the chin-groove, 

 although apparently useful in discriminating species, does not 

 help in the division of the Boidse into the two groups Pythoninaj 

 and Boinae ; for in Python spilotes I found seven scales on one 

 side and eight on the other side of the groove, and in P. regms 

 four on each side. In examples of Python sebce and P. molurus 

 there were eight of these scales on each side. 



As to the anal claios, I have unfortunately no observations 

 upon these in Corallus maclagascariensis ; but in Gorallus cookii 

 they were present and similar in both sexes, being sharp and 

 curved. Each was ensheathed in two or occasionally three bract- 

 like scales, which were situated on the concave side of the claw. 

 In this latter feature Corallus appeal's to agree rather with 

 Eunectes than with Poa ; foi' in the latter genus the claws are 

 ensheathed (in both sexes of Eunectes notceics) by two scales, 

 while in both Poa constrictor and P. diviniloqua the female snake 

 possesses a small sharp claw which does not appear to be ensheathed. 



§ Lungs. 



Although, as I shall take occasion to point out immediately, 

 the lungs of Corallus cookii present certain variations in structure 

 in the individuals of that species, they all agree to difier from 

 those of Corallus madagascariensis in one important particular. 

 The latter species on the whole resembles the genus Boa, in that 

 the bronchvis of the lai'ger of the two lungs extends for a long 

 way into its interioi- as a shallow gutter ; in fact, to a point beyond 

 the commencement of the liver. I may take this opportunity 

 of recording the fact that in Eryx conicus *, a representative 

 of a genus undoubtedly belonging to the Boine as contrasted with 

 the Pythonine section, the larger lung is also provided with a 

 very long intrapulmonary bronchus. I have found the same in 

 the Indian Ei'yx johni. In an individual of the former snake 

 I found that the bronchus was continued down to a point corre- 

 sponding with certainly the end of the first third of the liver, 

 and that it reached the region of the lung, where it ceased to be 

 vascular. In this snake I noticed a further peciiliarity in this 

 bronchial gutter : the " gutter " itself was of course in free com- 

 munication with the interior of the lung, as the word used to 

 describe it implies ; but, in addition to this, a series of small 

 perforations, quite numerous and regularly arranged in pairs, put 

 the cavity of the gutter into communication with that part of the 

 lung which was covered over by the semirings of the bronchial 



* In Cuviev's 'Le9ons d'Anatomie Compavee,' ed. 2, t. vii. 1840, p. 137, tlic same 

 is stated of " ErLv turcicns " (= Eryx jaculus). 



