148 ZOOLOGY. 
each side. There are two stemmata; the mouth is provided with a tongue, — 
two lancet-shaped palpi, and a pair de long slender mandibles with serrulate 
edges. The maxillary palpi have four articulations, and are so long that 
they resemble antennee (the antennee being facanepaceney: and below these 
there are two maxille, shaped like triangular plates. The antennz are 
minute, situated behind the stemmata, and capable of being hidden in a 
cavity. The feet are long and bristly, and adapted for leaping, and the 
tarsi are pentamerous. The larva of the flea is a slender white active grub, 
without feet, but it is provided with antennee, and a pair of posterior hooks. 
It attains its full size in about twelve days, when it spins a silken cocoon, 
and becomes a quiet pupa, in which the ails of the imago are visible. , 
Fleas (Pulec irritans, pl. V7, fig. 73ab) abound where there are dogs — 
and hogs; in camps and barracks, where they often swarm in the quarters 
of the elders: The larva seems AoE to be parasitic, living upon the litter 
of stables, &c. They are often produced from eggs laid under the toenails, 
or in the seams of the drawers of uncleanly persons, where they find 
nourishment adapted to their wants. 
Pulex penetrans (pl. TT, fig. T2abed), the type of Guérin’s genus 
Dermatophilus, is a small species which lives parasitically beneath the skin 
of the feet of men and dogs in the warm parts of America, particularly 
Guiana and Brazil. It is iowa as the jigger (chegoe, ciao). and by a 
dozen other names. It is found in sandy places, where it hops about like 
the other species, until it finds a suitable resting-place, when it penetrates 
beneath the skin and forms serious sores. In this condition the abdomen 
of the female enlarges to the size of a small pea (fig. 72c, enlarged and 
inverted), and is found to be full of eggs. The male has not been observed, 
and is probably not parasitic. They frequently lodge in the toes, especially 
beneath the nails, causing great pain and inflammation, and it sometimes 
happens that the toes must be amputated, in consequence of the sores to 
which they give rise. Waterton saw the foot of a negro which was a mass 
of ulcers from the neglected attacks of this insect. According to this 
author, ‘‘ The Indian and Negro wenches perform the operation of extract- 
ing chegoes with surprising skill. They take a pin, and by a very slow 
process, they lay the part bare, and contrive to work quite round the bag 
which contains the chegoe and its offspring. As soon as this has been 
effected, they turn the bag out, whole and uninjured ; by which means none 
are left in the hole to form a new colony.” Besides man and dogs, the 
sand flea attacks sheep, goats, cats, hogs, oxen, horses and asses. Accord- 
ing to Azara, it does not extend beyond 29° of south latitude. 
Oxper 4. CoLrorrera (pl. 81, figs. 84-148). This order includes all the 
insects with thin membranous wings on the metathorax, covered by hard cori- 
aceous wing-covers or elytra attached to the mesothorax, their colorand texture 
having more or less resemblance to the general exterior surface of the body. 
The mouth is mandibulate, and the wings folded transversely to allow them to 
be withdrawn beneath the elytra. There are, however, exceptions to most of 
the characters by which groups in the animal kingdomare defined. The wings, 
and even the elytra, are sometimes wanting. The elytra, which unite in a 
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