l>l LL1 riN W 1-1 ONSIN N \ r l RAL HlSTORl SOCIETI [Vol. 13, No. 2 
9G 
“Legs dark, last femur black; furcifer, villosipes, cornutus, 
lentulus , 1 australis. 
“Legs paler, last femora largely pale; pallidus, submedianus , 
subapicalis.” 
To the first of these groups we would add Gomphus whedoni 
Muttk.. of which a new figure is published with this paper (figure 
b). Gomphus whedoni is a close relative of G. cornutus, though 
distinct by the form of the appendages. 
In Williamson’s grouping Gomphus cornutus is a discordant 
element, as will be readily seen from a comparison of William- 
son's summary and the present description of the female G. 
cornutus. There are a number of points of disagreement. 
“Thorax green, varying in shade with age, sex, and species, 
and with distinct markings if present confined to the region of 
the mid-dorsal carina and the humeral suture.” Our descrip- 
tion states “lateral sutures with or without markings.” In 
t lie Wisconsin female these are very distinct and present on all 
thoracic sutures. 
“Hind femora extending be} r ond the auricles.” This is cor- 
rect for the males. In the Minnesota female the femora reach 
nearly to the tip of segment two; in the Wisconsin female 
the femora reach beyond the base of three, covering about one- 
fiftli of the segment. It was this enormous elongation of the 
posterior femora — a truly Dromogomphus feature — which was 
one of the features which prevented certain identification of 
the Wisconsin female until bred specimens were obtained. 
“Legs dark, last femora black” (referring to the larger group 
of Arigomphus). Our females: all femora black beneath. The 
hind femora of the Minnesota specimen are largely yellow, with 
apical dashes of black. In the males only the fore femora are 
yellow beneath. All tibiae of male and female black. 
According to these color differences, Gomphus cornutus cannot 
be said to occupy a true position hi the larger Arigomphus division, 
but rather a position intermediate between the larger and smaller 
group. 
Among the six species of the larger group G. lentulus and austra- 
lis , villosipes and furcifer, and cornutus and whedoni form natural 
relatives. G. lentulus tends toward suffusion of the markings 
1 Set* note by senior author at end of this paper. 
