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Show • 1904.] ANATOMY OF THE LACERTILIA. 467 branch in Iguana arises further back upon the carotid stem and has a shorter course before dividing into its several branches. The Lungs and their attachment.-Mr. G. W . Butler* has pointed out that "the Teiida? are the only family in which I have met with the condition in which the lung of each side is suspended freely by its more dorsal ligament, with a consequent absence of pulmo-hepatic recess." f In an accompanying diagram the absence of any pulmo-hepatic ligament is shown and contrasted with its presence in such a type as Iguana. As a matter of fact, Tiliqua scincoides agrees with Tupinambis in the free suspension of the right lung; but in both of them the difference from Iguana &c. is only a difference of degree. In both of the former genera there is a short membrane attaching the right lung to the anterior part of the liver; it is obvious, though rudimentary. A difference which Tupinambis shows from some other types in the attachment of the right pulmonary membrane is this: in the Teguexin the suspensory ligament is attached up to the very tip of the lung and extends considerably beyond the lung, ending, as it does, upon the posthepatic septum. Anteriorly the membrane is attached to the hepato-cesophageal ligament; it is then attached to the cesophagus at its dorsal border and so continues to the end. In Tiliqua the pulmonary ligament does not extend to the tip of the lung ; it is inserted at first on to the cesophagus, and more posteriorly, where the cesophagus bends to the left, to the ligament, continuous with the hepato-cesophageal ligament, which binds the liver to the mid-line of the dorsal parietes. On the left side the pulmonary ligament again extends to the very tip of the lung in Tupinambis. The membrane is attached first to the gastro-hepatic ligament; it then becomes inserted on the stomach and is continued backwards through the large foramen in the posthepatic septum on the left side, whence it may be traced as far as the spleen and the left gonad. The spleen and the left gonad, it may be remarked, lie much closer together in this lizard than they do in either Iguana or Tiliqua. In the two latter genera the pulmonary ligament of the left lung does not cpiite reach the end of that viscus; moreover, from the very first there is an attachment to the cesophagus, a separate fold of membrane in both these types binding the left lung to the gastro-hepatic ligament. Posteriorly the left pulmonary ligament may be observed to reach the spleen but not the gonad. The Liver, its Suspensory Ligaments and Veins.-The liver of this reptile is figured by Butler J in several aspects ; but the shape of the liver in the example studied by myself is not quite identical. It must be borne in mind, however, that we are dealing with different species. The falciform ligament suddenly bends to the left and lies in a, cleft of the left lobe of the liver into which enters * Loc. cit. p. 465. f Later, however (P. Z. S. 1892, p. 481), he finds that certain skinks agree with the Teiidae more or less. X Loc. cit. pi. xlviii. figs. 31, 33, 34. PROC, ZOOL, Soc-1904, VOL, I, No, XXXI. 31 |
