252 THE AMERICAN NATURALIST. 
of illustration Iadd a sketch of the upper surface of the head 
of a normal specimen (Fig. 1). : 
In considering the cause of this malformation I was attracted 
by the pit in the inter-prefrontal suture, and it at once struck 
me that it was located in the fontanelle, between the nasals and 
the frontal bones. The meeting point of the inter-supraocular 
suture with that of the inter-parietal suture also shows soft 
skin. The median suture between this point and the pit cor- 
responds to the suture between the frontal bones. A sketch of 
the top of the skull of the species is added (Fig. 3) to make 
Diagrams of top of head of Coluber obsoletus. Fig. 1. — Normal specimen. Fig. 2. — Malformed 
specimen. Fig. 3.— Top of skull: /, frontal bone; a, maxillary; n,‘nasal; o, orbit; 
P, parietal; fmx, premaxillary; 4x/, prefrontal. 
these points clear. Knowing the regenerative power of the 
reptilian tissues, I could not escape the impression that the 
true explanation of the malformation is an injury to the skin 
of the top of the head, by which the whole derm from the ros- 
tral to beyond the posterior end of the frontal became removed. 
In healing, the covering of the wound probably started from 
the edges of the lacerated adjoining scutes, which continued to 
grow until they met on the mesial line. In the sketch (Fig. 2) 
I have indicated by a dotted line the probable extent of the 
injury, but Iam bound to add that there is no indication in 
the specimen. It must be remembered that the epidermal cov- 
ering is regularly shed, and that the outline of the wound which 
probably was visible in the first covering may have disappeared 
in the succeeding molts. 
