98 J. E. 1NGPEN ON SCALE EVOLUTION. 



Many more transition forms could be shown, but those illus- 

 trated will, I think, be sufficient for the purposes of this paper. 



I have used the terms lines, striae, etc., in our ordinary micro- 

 scopical sense, to indicate general appearances rather than the exact 

 structure of the hairs and scales. 



In conclusion, I must thank Mr. Karop for his kind assistance 

 and admirable illustrations. 



