Xll INTRODUCTION. 
IV. NEUROPTEROUS. Having four membranes and semi-transpa- 
rent wings, veined like net-work; and the tail without a 
sting, as the dragon-fly and ephemera. 
V. HYMENOPTEROUS. Having four membranous and semi-transpa- 
rent wings, veined like net-work ; and the tail armed with a 
sting, as the wasp and bee. 
VI. DIPTEROUS. Having only two wings, as the common house- 
flies. 
VII. APTEROUS. Having no wings, as the spiders. 
The sixth, and last Linnaean class consisted of Worms, or 
Vermes. These are slow of motion, and have soft and fleshy bodies. 
Some of them have hard internal parts, and others have crustaceous 
coverings. In some of the species, eyes and ears are very per- 
ceptible, whilst others appear to enjoy only the senses of taste and 
touch. Many have no distinct head, and most of them are destitute 
of feet. They are, in general, so tenacious of life, that parts which 
have been destroyed will be reproduced. These animals are prin- 
cipally distinguished from those of the other classes by having 
tentacula, or feelers, and they are divided by Linnaeus into five 
Orders. 
ORDERS OF VERMES, OR WORMS. 
I. INTESTINAL. Are simple and naked, without limbs; some of 
them live within other animals, as the ascarides and tape- 
worms ; others in water, as the leeches ; and a few in the 
earth, as the earth-worm. 
II. MOLLUSCOUS. Are simple animals, without shell, and furnished 
with limbs, as the cuttle fish, medusae, star-fish, and sea- 
urchin. 
III. TESTACEOUS. Are animals similar to the last, but covered 
with shells, as oysters, cockles, snails, and limpets. 
IV. ZOOPHYTES. Are composite animals, and appear to hold a 
rank between animals and vegetables ; though they are in 
fact true animals, and possess sensation and voluntary mo- 
tion. In many instances a great number of them inhabit the 
same stone, but some are soft, naked, and separate. The 
coral, sponge, and polypes are instances of this order. 
V. ANIMALCULES Are destitute of tentacula or feelers, and are 
generally so minute as to be invisible to the naked eye. 
They are chiefly found in different infusions of animal and 
vegetable substances. 
