354 ANIMALS OF NEIGHBOURHOOD OF EGA. Cuap. XII. 
a small number exists) I have watched them buffeting with the strong 
winds at the commencement of the dry season, and as the dryness in- 
creased, disappearing from the locality. On ascending the Tapajos to 
the calm and sultry banks of the Cupari, a great number of these insects 
reappeared, most of them being the same as those found on the Upper 
Amazons, thus showing clearly that their existence in the district 
depended on the absence of winds. 
Before proceeding to describe the ants, a few remarks may be made 
on the singular cases and cocoons woven by the caterpillars of certain 
moths found at Ega. The first that may be mentioned is one of the 
most beautiful examples of insect workmanship I ever saw It is a 
cocoon, about the size of a sparrow’s egg, woven by a caterpillar in 
broad meshes of either buff or rose-coloured silk, and is frequently seen 
in the narrow alleys of the forest, suspended from the extreme tip of 
an outstanding leaf by a strong silken thread five or six inches in length. 
It forms a very conspicuous object, hanging thus in mid-air. The 
glossy threads with which it is knitted are stout, and the structure is 
therefore not liable to be torn by the beaks of insectivorous birds, 
whilst its pendulous position makes it doubly secure against their 
attacks, the apparatus giving way when they peck at it. There isa 
small orifice at each end of the egg-shaped bag, to admit of the escape 
of the moth when it changes from the little chrysalis which sleeps 
tranquilly in its airy cage. The moth is of a dull slaty colour, and 
belongs to the Lithosiide group of the silk-worm family (Bombycidz) 
When the caterpillar begins its work, it lets itself down from the tip of 
the leaf which it has chosen, by spinning a thread of silk, the thickness 
of which it slowly increases as it descends. Having given the proper 
length to the cord, it proceeds to weave its elegant bag, placing itself in 
the centre, and spinning rings of silk at regular intervals, connecting 
them at the same time by means of cross threads; so that the whole, 
when finished, forms a loose web, with quadranguiar meshes of nearly 
equal size throughout. The task occupies about four days: when 
finished, the enclosed caterpillar becomes sluggish, its skin shrivels and 
cracks, and there then remains a motionless chrysalis of narrow shape, 
leaning against the sides of its silken cage. 
Many other kinds are found at Ega belonging to the same cocoon- 
weaving family, some of which differ from the rest in their caterpillars 
possessing the art of fabricating cases with fragments of wood or leaves, 
in which they live secure from all enemies whilst they are feeding and 
growing. I saw many species of these; some of them knitted together, 
with fine silken threads, small bits of stick, and so made tubes similar 
to those of caddis-worms ; others (Saccophora) chose leaves for the 
same purpose, forming with them an elongated bag open at both ends, 
and having the inside lined with a thick web. The tubes of full-grown 
caterpillars of Saccophora are two inches in length, and it is at this 
stage of growth that I have generally seen them. They feed on the 
leaves of Melastome, and as, in crawling, the weight of so large a 
dwelling would be greater than the contained caterpillar could sustain, 
the insect attaches the case, by one or more threads, to the leaves or 
twigs near which it is feeding. 
