308 DIVISION III. ARTICULATED ANIMALS.—CLASS IV. INSECTA. 
“The larva are changed into perfect insects, which take up their abode 
permanently on the branches of the cacti. The Mexicans gather them as 
soon as they have reached the perfect state. The harvest cannot be difficult, 
considering the immobility of these little creatures. When collected, the 
cochineals are killed, packed in wooden boxes, and sent to Europe, to be 
used in dyeing.” 
ORDER VIII. NEUROPTERA. 
The fore wings of the Neureptera are membranous, naked, transparent, 
and furnished with a very fine network of lines like nerves, whence the name 
of the order, Neuroptera — nerve-wings. The mouth is fitted for biting, 
the mandibles and maxille being corneous and very strong. 
These insects constitute the genera Libellula (the Dragon-flies), the 
Ephemera, Panorpa, Myrmeleon, Hemerobius, Termes, and Phryganea, 
which again are divided into many subgenera and numerous species, as 
LipeLLuLa. — These insects are well known under the name of Dragon- 
flies. They are distinguished by their large, gauze-like wings, which enable 
them to fly with great swiftness in the pursuit of their prey; their varied 
and often brilliant colors; their slender body; large, rounded head, and 
great eyes. 
L. Depressa. — The typical species, LZ. cancellata, are distinguished by 
the fine leaden-blue color of the abdomen. 
L. Grandis is two and a half inches in length, is swift of flight, and 
skims near the surface of the water, and through the air, in the manner of 
swallows. 
L. Virgo is of a golden-green color, with wings of blue, and sometimes 
of a pale-brownish yellow. 
All the Dragon-flies have similar habits. 
The author of “ Mémotres pour servir & UEistoire des Insectes” furnishes 
the following interesting facts regarding them : — 
Nothing is prettier than a troop of Dragon-flies taking their sport on the 
side of a pond, or on the banks of a river, on a fine summer’s day, when a 
burning sun causes their wings to shine with most vivid colors. 
In the perfect state, as well as in that of the larva and the pupa, the Libel- 
lulas are carnivorous. Their rapid flight makes them expert hunters, and 
their enormous eyes embrace the whole horizon. They seize, while on the 
wing, flies and butterflies, and tear them to pieces immediately with their 
strong mandibles. Sometimes, the ardor of the chase leading them on far 
from the streams, they are met with in the fields. 
The female lays her eggs in the water, from which emerge larve which 
