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Show 1 9 0 6 .] RESPIRATORY SYSTEMS IN THE OPHIDIA. 5 1 9 actually the case. For the shorter the tract of bronchial semirings within the lung, the longer the seam running down that organ. The lungs of Corallus therefore conform to the usual Boid 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 Corallus, coupled with its inclusion within the Boine section of the Boidae. The only other organs which I have especially noted are the kidneys, and this by reason of the fact that they offer characters of systematic value in discriminating certain Ophidia. In Corallus, 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 Corallus are deeply separated into lobes, more so than can be noted in some Snakes. Finally, the present genus agrees with other Boidae 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 Boidae, and, so far as present observations enable a statement, is only found in Ilysia outside that family; Hysia has also other Boine characters*. (4) On the Modifications o f Structure in the Lungs of certain Ophidia. The most recent general paper dealing with the lungs in the Ophidia is by the late Prof. Copef, who refers in that communication 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 Boidae of two functional lungs, a right and left, of which the right is the larger; (2) that other Snakes have only one functional lung, which Butler i 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. f " 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. |
