COLLINGK : ON THE ANATOMY OF THE VITRINA IRRADIANS. 69 



short labial muscle is given off, while from the superior ocular, the 

 short pedal muscles arise. The columellar muscle is small, and divided 

 into four main branches. 



The raUial Region (PI. vi, fig. 13). — The kidney is short, being 

 only a little over twice the length of the pericardium. The ureter 

 arises from the left anterior side of the kidney, it is very wide, and 

 forms a conspicuous V-shaped tube. Unlike the condition obtaining 

 in some of the Indian species of Nihjiria, the kidney does not extend 

 to the side of the rectum, but terminates bluntly before the bend of 

 the ureter. The pulmonary cavity is comparatively small. 



Affinities. — So little detail is known of the anatomy of what at first 

 sight appear allied genera to Ratnadvipia, that it is difficult to institute 

 comparisons. I have examined the internal structure of different species 

 of Nilgiria, to which genus the one under discussion is probably 

 nearly related, but until I have worked out the same in greater detail, 

 and know the anatomical position of Nihjiria, I prefer to reserve any 

 expression of opinion. 



For Explanation of Plates and Reference Letters, see next page. 



