THE PENCIL-TAIL . 
525 
line traversing the middle of the under surface, and that when the creature is walking, their 
extremities do not project beyond the edges of the shelly covering. 
Like the armadillo-woodlouse, the Pill -millepede was formerly used in medicine, prob- 
ably because it looks somewhat like a pill, and may be found among the old stock of drug- 
gists’ shops, mixed with the veritable armadillo. Both these beings feed on the same sub- 
stances, namely, decaying animal and vegetable matter. It seems to be rather a gregarious 
creature, as it is generally found in tolerable numbers in some favored locality. 
a We now come to another genus, termed Polydesmus. This term is composed of two 
Greek words, the former signifying “many,” and the latter a “bundle,” in allusion to the 
numerous groups of limbs arranged along the body. In all these creatures the body is 
covered with a hard skin, and the segments are flattened and lengthened at the sides. A 
handsome species, called Polydesmus splendidus, is found in India, and mostly attains the 
length of two inches. The color and general aspect of this species are rather striking. Inde- 
pendently of the very deep depression of the segments, which has a very strange effect, the 
color is bold and striking, being deep and very reddish-brown, diversified by an angular spot 
of bright yellow placed in the hinder angles of each segment. The body is smooth and 
slightly shining. When alarmed it is able to roll itself into a partial spiral, so as to present 
merely the hard shelly armor to the foe, and to shield the limbs within the coil. 
To a. new species belonging to this genus, I propose to give the specific name “granu- 
latus,” on account of the peculiar appearance of the body, which is thickly covered with very 
minute raised tubercles of a white color, such tubercles being called granules in scientific 
nomenclature. Perhaps I can give a better notion of the idea expressed by the word “granu- 
lated,” by mentioning that it could be rightly applied to such substances as shagreen. 
The general color of this species is rather dark drab, and it may be at once recognized by 
the peculiar form of the segments, which are flattened and elongated even more than usual in 
this genus, and are set at their extremities with three distinct teeth. The length of the speci- 
men from which this description is taken is rather more than three inches. 
A species of this genus ( Poly- 
desmus comjplanatus ), represented in 
the accompanying illustration, is 
found in Europe, and is not uncom- 
mon in gardens. It is about three- 
quarters of an inch in length, is very 
narrow, and has thirty-one pairs of 
feet. The genus is a very large one, 
and contains a great number of exotic 
species. The figure of the engrav- 
ing is magnified. 
Before passing to the next large 
family of myriapods, we may men- 
tion the pretty little Pencil-tail 
( Polyxenus lagurus ), a tiny creature which seldom attains a greater length than the twelfth of 
an inch. It is found under the bark of trees, in clefts of walls, and in moss, and may be known 
by the twelve pairs of feet, the bunches of little scales on the sides, and the white pencil at 
the end of the tail. 
The members of the curious family Julidse are very like those which have just been 
described, but may be known from them by the fact that the edges of the segments are not 
flattened and lengthened, but are continued in an unbroken circle. They feed mostly on 
decaying vegetable matters, but have been seen to eat dead earth-worms and mollusks. 
They all exhale a peculiar and rather unpleasant odor, which is caused by a fluid secretion 
in certain little sacs along the sides, two on each ring. The little apertures through which 
this scented fluid exudes may be seen on examining the creatures closely, and by some of the 
earlier writers they were mistaken for spiracles, the sacs themselves being thought to be the 
POLYDESMUS . — Polydesmus complanatus. 
