152 



MK. F. E. BEDBARD OX THE VISCERAL 



[June 7, 



very long and thin, measuring, as has been mentioned, 2| inches 

 each. Wliile, thei-efore, the body of Platyitrus is rather more 

 than half the length of that of Hydrus, the kidneys of the latter 

 are five times the length of those of the formei- genus. They do 

 not, howeveji', seem to me to be much, if any, greater in bulk, 

 since they are extremely thin and narrow, while those of 

 Platyurvs are wider in proportion to their length. Another 

 difference shown by the kidneys of the two genera is the extent 

 to which they overlap. In Platym-ns the two kidneys hardly 

 overlap at all, whereas in Hydras the right anterior kidney 

 extends alongside of the first two inches of the left kidney. There 

 is thus a considerable approximation here towards symmetrical 

 kidneys. 



§ Luny, 

 The lung-tissue is recognisable fi'om two and a quarter inches 

 behind the tip of the snout. It begins, therefore, very early in 

 tlie neck. The lung-tissue begins gradually between the dorsal 



Text-fiy. 27. 



A portion of the internal surface of the lung- of Hjjdrtis platynvtis. 



non-fused ends of the tracheal rings. This snake has therefore, 

 as has been stated, a ti-acheal lung. The trachea, moreover, is 

 open throughout into the hnig, and forms in fact only a gutter 

 along its ventral surface. The neck of this serpent is short, and 

 therefore the tracheal lung is not of great extent ; it appears to 

 cease about half an inch in front of the heart, and therefore has 

 not a course of more than two inches. A sudden widening at that 

 point I take to be the commencement of the bronchial lung. 

 There is no other differentiation that I can detect. The inner 



