112 



MR. W, BATESON ON 



[Feb. 2, 



Fig. 5. 



^ 7i /a Of pb 



Oa 



Upper Diagram. 

 Teeth of Bhinoptera javanica, specimen haying asynimetrical dentition (after 

 Smith Woodward). The arrangement on the right side of the figure is 

 normal. The lettering shows Mr. Woodward's suggestion as to the cor- 

 respondence of the parts. 



Middle Diagram. 

 Rhinopiera sp. inc. From a Hunterian specimen in the Museum of the College 

 of Surgeons. On the left side there are three rows of small lateral teeth, 

 while on tiie right side two of these rows are represented by one row, 

 which in places shows an indication of division. 



Lower Diagram. 

 Bhinoptera javanica, in which the row of teeth marked I. is on the other side 

 represented by two row.s. (After Owen, ' Odontography,' pi. xxv. flo-. 2. 

 From a specimen in Coll. Surg. Mus.) 



IfoTE. — That in these two cases, though the general proportions are maintained, 

 the lines of division between, the lateral plates on the abnormal side are 

 not in their normal morpbological positions relatively to the median 

 plates, the interspaces on the one side corresponding to the teeth on the 

 other. 



