44 
Fig. 1. Gamasus Coleopteratorum is an oval 
reddish brown mite, which is often found in con- 
siderable numbers on dung beetles and burying 
beetles. 
Dermanyssus hirundinis, the Swallow Mite, lives 
in swallow’s nests, and sometimes also attacks caged 
birds, pigeons and fowls. They hide themselves by 
day in the crevices of the nest or cage, and only 
attack the birds at night. 
Family IV. Tyroglyphide. These are very 
smaJl and mostly microscopic mites, 
with oval bristly bodies. 
Fig. m. TZyroglyphus siro, the 
Cheese Mite, is white and brownish, 
and about one-twenty-fifth of an inch 
long. It swarms in old cheese. 
Family V. Sarcoptide. The Itch” J 
Mites are parasitic in the skin of MAN ign Mite (Sar 
and other animals, or live in decaying 
5 5S coptes hominis) 
animal and vegetable matters. Mapnifasidiareterst 
Class My 


Sarcoptes hominis bores in the skin of man, 
and thus occasions the disorder known as the itch. 
Family VI. Ixodid#. The Ticks are of com- 
paratively large size. The proboscis is large and 
prominent, and the skin of the abdomen is folded 
and extensile. They suck the blood of any animals 
which come to their way. 
Fig. n. Ixodes ricinus, the Dog-Tick, is of a 
leaden grey, and as large as a hemp-seed. It lurks 
in grass and bushes, and when it attaches itself to 
the skin of a passing animal, it sucks the blood till it 
It is easily 
swells itself to the size of a small bean. 
got rid of by rubbing with oil. 
Family VII. Derma- 2 
tophilide. These are micro- © 
scopic animals, which are 
parasitic in the skin. 
Dermodex hominis lives 
ia the sebaceous cavites at 
the roots of hairs on the ears and nose of man. 

Dermodex hominis 
(magnified 600 diameters). 
rliopoda. 
Plate XXUI (right hand). 
These animals have long bodies composed of 
many nearly similar joints, each of which is provided 
with one or two pairs of legs. There is no division 
The head is distinct, 
and there are two antenne. The eyes are rudimentary. 
They breathe by means of trachex. On quitting the 
egg, the creatures are without legs, or have only 
3 pairs of legs, and increase the number of their 
segments and legs at each moult. They live chiefly 
in dark damp places, or under stones, and feed on 
between thorax and abdomen. 
decaying animal and vegetable matters. 
. | e 
Section 1. Chilopoda. 
In the Centipedes, each segment bears only 
one pair of legs. The antenne are long. The bite 
of the larger species is venomous. 
Fig. a. Scolopendra morsitans is brown, and 
the segments are of nearly equal length, the last 
with 3 spines. It lives in Central America, and is 
often brought to Europe in ships. Its bite causes 
great pain for a long time afterwards. 
Fig. b. Lithobius forficatus is greyish-brown 
with a reddish lustre, and has 14 pairs of legs. The 
segments are of unequal size. It is found under 
stones and in the ground, and feeds on worms. 

Section H. Chilognatha. 
In the Millepedes the body is wormlike or 
much flattened, and every segment is provided with 
2 pairs of legs. The antenne are short, and 7-jointed. 
They feed on plants at night, and are found in all 
parts of the world. In Europe they are of moderate 
size, but in hot countries they often attain the length 
of nearly a foot. 
Family I. Julida. These roll themselves up 
into a spiral form, and hibernate in this position, 
Fulus terrestris is ringed with yellow, and has 

99 pairs of legs. It is found among dead leaves or 
under stones. 
Family I] Glomerida. These have long oval 
bodies, arched above, and 17 pairs of legs. 
Fig. c. Glomeris limbata is of a shining 
blackish brown with yellow rings. It is a common 
species, and lives singly or in company under stones 
and fallen leaves. 
Class Crustacea. 
(Plate XXVIL) 
Among the large numbers of existing animals | 

we frequently meet with small groups which are ex- 
: ; : | 
tremely interesting to everyone who tries to trace | 
out the relationships between the various forms of | 
- . an | 
the animal kingdom, because they appear to be | 
related to more than one sharply defined group. 
Some of these are perhaps related to extinct groups, 
and are placed by naturalists with one class or 
another, as their views of their affinities vary. 
We have now two such groups to consider, 
