968 DIVISION Ill. ARTICULATED ANIMALS.—CLASS III. ARACHNIDA. 
ORDER II. OF ARACHNIDA. TRACHEARLZE. 
This order is divided into three families, the first of which is composed of 
the Pseudo-Scorpiones — False Scorpions. With the exception of one or 
two species discovered in Cuba, they inhabit the hot countries of the Old 
World. They are small animals, having from two to four eyes, can run 
with considerable swiftness, often sidewise, like the crab, dwell beneath 
stones, decaying bark, and sometimes in old books and herbariums. 
In the second family are the Pycnogonides. These are marine animals, 
found among marine plants, under stones near the shore, and sometimes on 
whales. . 
In the third family are several genera, which contain a large number of 
well-known species. The most of them have eight legs, although some have 
but six. 
PraLtancium. — This genus comprises those singular-looking animals 
called Harvest Men. They have eight very long legs, which, when de- 
tached from the body, exhibit, for some time, signs of life. Most of them 
live on the ground at the roots of trees, and are very active; others conceal 
themselves beneath stones, or in the moss. 
Tromprpium, Fabr., has the chelicer terminated by a movable claw ; 
palpi projecting, pointed at tip, with a movable appendage or finger beneath 
the extremity; two eyes, each at the top of a small, fixed peduncle. 7. 
holosericeum, Fabr., very common in gardens during spring, of a blood- 
red color, with the abdomen nearly square, and narrowed behind. A much 
larger species (JZ. cinctortum, Fabr.) inhabits the East Indies, and emits 
a red dye. 
Eryturmus, Latr., has the chelicere and palpi of Trombidium, but the 
eyes are sessile, and the body not divided. 
Gamasus, Latr., has the chelicerw didactyle, and the palpi projecting, 
distinct, and filiform. In some the body is covered entirely, or in part, by 
a scaly skin, but in others it is entirely soft. Some of the latter species live 
upon different birds and quadrupeds ; others, as the Acarus telart tus, Linn., 
or the Red Spider of the hot-houses, form upon the leaves of various vege- 
tables, especially upon those of lime trees, very fine webs, which injure 
them greatly. This species is reddish, with a black spot on each side of 
the abdomen. 
Acarus. — The Acarides are universally distributed. Some are wander- 
ers; and, amongst these, some are found under stones, leaves, the bark of 
trees, in the ground, the water, or upon provisions — such as flour, dried 
meat, old dry cheese, and upon putrid animal matters. Others subsist as 
