150 MK. F. E, BEDDARD OX THE ANATOMY [Mav. 3, 



very near to, the more distantly situated spleen. As the Boidre 

 are believed, by reason of a considerable number of anatomical 

 peculiarities, to stand at the base of the Ophidian sei'ies, this fact 

 is obviously not without importance. 



§ Belative Position of Viscera. 



The relative position of the viscera among snakes and their 

 proportionate lengths are important as diagnostic characters. 

 Thus, in the Tipei-ine Serpents the liver follows close upon the 

 heart, and in the Boidfe the kidneys have rather a diflerent 

 position from that in the case of other Ophidia. It is not, there- 

 fore, Avithout importance to compare the two species of Cor alius 

 in these particulars. 



C. Madagascar iensis. C. cookii. 



Total length to vent 50 inches. 6-i inches. 



From symphj'sis of jaws to auricles 



of heart ? ISi- inches. 



From apex of heart to beginning of 

 liver Scinches. 4f inches. 



Length of liver 12|^ inches. 11 inches. 



Distance between end of liver and 



gall-bladder ^ inch. 8 inches. 



Length of kidneys If inch. 3^ & 2| inches. 



Distance of end of posterior kidney 



from vent About 5-6 inches. 10 inches. 



It is obvious from the above measurements that there are 

 difierences between the two species, which cannot by any means 

 be accounted for by the differences in length which they show as 

 individuals. Thus one kidney, at any rate, of CoraUus cookii is 

 twice the length of that or rather those of CoraUus madagas- 

 cariensis, although the length of the snake is only one-fifth or 

 one-sixth greater. Furthermore, the distance of the kidneys 

 from the cloacal orifice in C. cookii is greater, both actually 

 and proportionately, than in C. madagascariensis. This Boine 

 chai^acter is therefoi'e more emphasised in the American than in 

 the Madagascar species. Although the liver of C. madagas- 

 cariensis is slightly longer than that of the American species, 

 this does not account for the great discrepancy which the two 

 species show in the distance of the gall-bladder from the end of 

 the liver. In Corcdlus cookii the two kidneys hardly ovei'lap. 

 The posterior kidney begins where the right kidney ends. I find 

 that here, as in the case with CoraUus madagascariensis and other 

 Boidfe, the kidney of each side is furnished with only a single 

 renal aitery. This structural fact can, as I think, be now 

 regarded as characteristic of the Boidte as compared with many 

 other snakes. 



