THE CANADIAN ENTOMOLOGIST 247 
On OctobcY 2 and 3, 1917, while in camp on the East Verde 
River, Arizona, at a point about ei^ht miles north of Payson, 
altitude 4,400 feet, I took two females of nasalis, and noted others, 
fl\'ing at the throat of my horse, but in no case did they alight 
there. They were seen to hover directly under the animal's 
throat, and then dart suddenly at the muzzle. I saw this opera- 
tion repeated many times before I was able to capture the fly, as 
this action of darting at the muzzle made the animal especially 
wild. On examination im.mediately thereafter, I found several 
whitish eggs with their sharp bases penetrating and adhering in 
the skin of the upper lip. These eggs were lost owing to the frantic 
struggles of the horse at the time, but similar eggs were dissected 
from the abdomen of the fly. 
The egg is practically the same size and shape as that of 
intestinalis and not at all like that of hacmon-hoidaUs, but the 
anal end is moderately pointed though somewhat blunt as seen 
under a high power. It is capable, however, of penetrating tender 
skin, as tested on the back of my finger. Moreover, the chitinized 
clasping forceps at the end of the heavy ovipositor are quite sharp 
in nasalis, while they are decidedly blunt in both intestinalis and 
haemorrhoidalis. 
On the East Verde intestifialis was common but caused no 
such alarm as did nasalis while ovipositing. No specimen of 
haemorrJwidalis was seen anywhere in that region. 
The above facts seem to indicate that nasalis oviposits about 
the muzzle of the horse, hovering under the throat merely as a 
preliminary while seeking a good opportunity to dart at the lips, 
and piercing the tender skin with the sharpened forceps of the 
ovipositor Avhile thrusting the anal end of the egg into the puncture. 
It seems further that this habit of darting at the muzzle of the 
animal was known to Linnaeus, else why should he have named 
the species nasalis? It appears that in later times the preliminary 
action of the fly in seeking the throat has been commonly observed 
and its darting thence to the muzzle, overlooked by some investi- 
gators though recorded by others, hence the mistaken opinion still 
held by some that it oviposited in the region of the throat. It is 
against all reason that the eggs should be placed under the throat. 
