SHORTER ARTICLES AND CORRESPONDENCE 



PECULIAR ABNORMAL TEETH IN A JACK-RABBIT 

 About ten years ago I saw a curious malformation in the skull 

 of a wood-chuck; the upper and lower incisors in some way 

 missed coming in contact with each other in the usual way and 

 had grown up and down through the skull and lower jaw, to 

 wind and twist about above and below completely locking the 

 jaws together. This animal was killed by a hunter near 

 Waverly, N. Y., and is now in the Museum of Cornell University. 



Since examining this first one, I have seen and heard of a 

 number of similar malformations and in all cases the teeth of 

 the upper and lower jaws grew more or less irregularly dorsally 

 and ventrally. 



A year ago at Claremont, Cal., another peculiar condition was 

 brought to my attention in the skull of a young jack-rabbit 

 (Figs. 1 and 2). In this skull the teeth are most remarkable 



in the lower jaw, here the two incisors have grown nearly 

 straight out some distance and are only slightly curved and 

 twisted upon each other. In the upper jaw the incisors are not 

 so long and only twisted at the tips. 



William A. Hilton. 



Pomona College, Claremont, Cal. 



799 



