248 University of California Publications in Zoology (Vou. 138 
in part to show the relation of the scalation to the segmentation of 
the musculature, but his description and figures indicate that modifi- 
cations of taxonomic value undoubtedly exist in the scales of reptiles. 
The scales of fishes have received more attention than any of the 
structures in other groups which in a general way are analogous, 
and these are the only integumentary growths, the morphologic modi- 
fications of which have heretofore been actually applied to taxonomic 
and phylogenetic problems. A series of papers by T. D. A. Cockerell 
(1909-1913) deals with the actual taxonomic application of scale 
structures, and gives keys to families and genera based on these char- 
acters. Cockerell (1911le and 1912) has shown that the scales of 
coeciliids also show characters which are of value in classification. 
In view of the fact that all these integumentary structures of 
vertebrates are homologous, or at least in a general way analogous, 
to each other, and that investigations of them, in a general way, 
present similar problems, and are governed by the same limitations, 
and in fact frequently overlap each other, it seems to the writer that 
a common name should be applied to the study of them. For this 
study, which shall include the study of the development, morphology, 
and phylogenesis of vertebrate scales, hair, and feathers, and any 
other homologous or analogous structures, the writer wishes to sug- 
gest the name Epiphyology (based upon emipverv, to grow upon) as a 
general term for the ‘‘study of outgrowths’. In creating this term 
it is admitted that the formation is not perfectly valid etymologically. 
TV. NoMENCLATURE AND DEFINITIONS 
It is unfortunate that in the literature of feathers there has been 
a very notable lack of uniformity in the use and meaning of terms, 
resulting in no little confusion and inconvenience, considerably more 
so among German writers, however, than among others. After a 
careful study of the history and usage of the nomenclature of feathers, 
the writer has selected a terminology which, taking all points of 
view into consideration, seems to be the most logical and widely 
applicable. These terms have been selected with regard (1) to the 
general usage, (2) to convenience, (3) to priority. It seems advisable 
to give a list of the terms here used to describe feathers, with their 
definitions, and in the case of terms which have been used inac- 
curately, the names of some of the authors who have used them in 
the sense here accepted. The more important synonyms are also given, 
