1906.] RESPIRATORY SYSTEMS IN THE OPHIDIA, 519 



actually the case. For the shorter the tract of bronchial semi- 

 rings "vvithin the lung, the longer the seam running clown that 

 organ. The lungs of CoraUus therefore conform to the usual 

 Bold pattern. They lean more towards the Boine than the 

 Pythonine structure, but offer differences of detail from those of 

 other genera which have been examined. These facts therefore 

 clearly justify the generic independence of CoraUus, coupled with 

 its inclusion within the Boine section of the Boid93. 



The only other organs which I have especially noted are the 

 kidneys, and this by reason of the fact that they offer cha- 

 racters of systematic value in discriminating certain Ophidia. 

 In Coralkcs, as in the Boidae generally, the renal glands lie at a 

 considerable distance from the cloaca. I did not make an absolute 

 measurement, since at the time I only noted that they appeared 

 to occupy much the same position as do those of Eryx, &c. 

 Furthermore, the kidneys are very small relatively speaking. The 

 two of them measure about an inch and three-quarters, and there 

 is not a great deal of difference between that of each side of the 

 body. The smallness of the kidneys is exactly the same as in the 

 cases of Eryx and Enygrus ; and, as in those two genera, the kidneys 

 of CoraUus are deeply separated into lobes, more so than can 

 be noted in some Snakes. Finally, the present genus agrees with 

 other Boidfe in the fact that each kidney is served by a single 

 renal artery. This latter appears to be one of the most decisive 

 characters of the Boidfe, and, so far as present observations enable 

 a statement, is only found in Ilysia outside that family ; Ilysia 

 has also other Boine characters*. 



(4) On the Modifications of Structure in the Lungs of 

 cei^tain Ophidia. 



The most recent general paper dealing with the lungs in the 

 Ophidia is by the late Prof. Copet, who refers in that com- 

 munication to some of the previous work upon the subject, mainly 

 to be found in Siebold & Stannius' well-known text-book. It 

 is now known, both from Prof. Cope's work and from the memoirs 

 of others, that the chief variations in structure which the lungs in 

 this group show are : — (1) the existence in most Boidse of two 

 f vinctional lungs, a right and left, of which the right is the lai-ger ; 

 (2) that other Snakes have only one functional lung, which Butler % 

 has proved to be the right in every case; (3) that the rudimentary 

 left lung may be altogether absent ; and (4) that the lung- substance 

 may exist from the very commencement of the trachea forming 

 the so-called "tracheal lung," which itself shows considerable 

 variations in its condition in different Serpents. 



To the facts collected together by these authors I have been 



* Beddard, P. Z. S. 1906, vol. i. p. 31. 



t " On the Lungs of the Ophidia," Proc. Amer. Phil. Soc. xxxiii. p. 217. 

 X " On the Complete or Partial Suppression of ... . the Left Lung in Snakes, &c.," 

 P. Z. S. 1895, p. 691. 



