ZOOLOGICAL NOMENCLATURE . 
7 
abbreviated if the context is such that the abbreviations will be read¬ 
ily understood. Thus the name of the Black Merlin may be written 
Fa/co c. suckleyi or F. c. suckleyi . 
Subspecific names are used by entomologists not only to distinguish 
geographical races, but also to distinguish the different forms of 
dimorphic and polymorphic species. A good illustration is afforded 
by a certain species of Swallow-tail Butterfly common in the Atlantic 
States. This species exists under two distinct forms; one of these is 
yellow marked with black, and has long been known as Jasoniades 
turnus; the other is almost entirely black, and has been known as 
Jasoniadesglaucus. At first it was supposed that these were different 
species ; but in recent years the two forms have been bred from eggs 
laid by the same female. It is thus evident that the two forms repre¬ 
sent a single species. And as the form glaucus was first described its 
name is given to the species, which is now known as Jasoniades 
glaucus . This name Jasoniades glaucus is used when reference is 
made to the species as a whole. But if one wishes to refer to the 
black form alone, it is distinguished as Jasoniades glaucus glaucus; 
while the yellow form is distinguished as Jasoniades glaucus turnus . 
In the illustrations just given the dimorphism occurs in the same 
generation. But many instances are known where the dimorphism is 
seasonal. Thus in the case of certain insects which pass through two 
or more generations in the course of a year, the different generations, 
or some of them, differ markedly in form or coloring from the others. 
These differences in many cases are so great that the different genera¬ 
tions of the same species were believed to be distinct species till they 
were bred from each other. It is therefore often desirable to distin¬ 
guish these different forms by subspecifk names. Thus Iphiclides 
ajax is a species of Swallow-tail Butterfly which exists under three 
distinct seasonal forms: an early spring form, I. ajax marcellus; a 
late spring form,/, ajax telavionides / and a summer form, /. ajax 
ajax. 
The name of a genus or of a subgenus is always a single word, 
and should be a noun in the singular number and nominative case. 
The names of all groups of genera (i.e., families, orders, classes, 
and branches) consist each of a single word , and this word should 
be a plural noun in the nominative case. 
The following practices regarding the forms of zoological names 
are now almost universally followed : 
The names of all groups in zoology, from kingdom to subgenus 
inclusive, are written and printed with a capital initial letter. 
