ABNORMALITIES IN CHFIONIA. 



i ;K \rrrM\s CKUIKAI-IIICX. 



CllKVSK.MVS MARC1NATA. 



ginals will usually settle the point, as the normal condition has a 

 very characteristic arrangement of these t\vo sets of elements. 



Another source of difficulty arises from the complete or in- 

 complete fusion of adjacent scutes. Fusion is due to the inhibi- 

 tion of the process of division into epidermal areas at a rather 

 late embryonic stage. In some cases the fused scutes show their 

 separate identity, after a year or two of growth, by a separation 

 of their growth rings. Coker has called attention to several such 

 cases in connection with Malaclcunnys ccntrata and I have 

 observed the same phenomenon in the marginals of Graptcinys 

 on several occasions. Usually, however, the indications are clear 

 enough to enable one to recognize the individual elements in a 

 fused scute. It seems reasonable in the present discussion to 

 consider the number of scute primordia involved in a fusion and 

 to give them the full rank of independent scutes. 



As in the previous tabulation, the arbitrary terms, large-, small 

 and medium, are used. Lor R in connection with neurals will 



