ARTHROPODA. 
2 54 
ANIMAL ACTIVITIES . 
CLASSES. 
Insecta. 
( Annulata. These are the more highly organized worms 
VERMES. ) like the earthworms and leeches. They are com- 
( monly regarded as a separate sub-kingdom or phylum. 
' Thysanura, spring-tails. 
Pseudo-neuroptera, dragon-fly. 
Orthoptera, grasshopper. 
Hemiptera, aphis. 
Neuroptera, ant-lion. 
Coleoptera, potato-beetle. 
Diptera, house-fly. 
Lepidoptera butterfly. 
Hymenoptera, bee 
! Spiders. 
Scorpions. 
Mites. 
j Centipedes 
] Millipedes. 
f Here belong the crayfish, lobster, shrimp, crab, 
J sand-hopper, pill-bug, asellus, cyclops, daphnia, 
I fish-lice, barnacles, and many other arthropoda 
[ which breathe by means of gills. 
Myriapoda. 
Crustacea. 
MOLLUSCA. 
CHORDATA. 
CLASSES. 
Pelecypoda, or bivalve mollusks, like clams, oysters, 
and scallops. 
Gastropoda, or univalve mollusks, like slugs and snails. 
Cephalopoda, including the squid, octopus, and nauti¬ 
lus. 
Amphineura, including the chitons. 
Omitting some low forms of somewhat doubtful re¬ 
lationship, we may call all animals belonging to this 
sub-kingdom Vertebrata and include them in classes as 
given below. 
CLASSES. 
Cyclostomi, including the lancelet or Amphioxus. 
Pisces, including all fishes. 
Amphibia, including frogs and their allies. 
Reptilia, including snakes and turtles. 
Aves, including birds. 
Mammalia, including the higher animals bearing hair 
or fur and provided with glands secreting milk. 
Man belongs to this class and to the order Primates, 
to which order the monkeys also belong. 
VOCABULARY. 
Am phi ox'us (Gr. amphi , on both 
sides), and oxys, sharp), a small 
fish-like vertebrate. It is also 
called the lancelet. 
An nu la'ta (Lat. annulus , a little 
ring), a division of Vermes in¬ 
cluding the common earth-worm. 
Archae op'te ryx (Gr. archaios , 
ancient, and pteryx , a wing), a 
fossil bird. 
A'ves (Lat. avis , a bird), birds. 
Di'a phragm (Gr. dia, through, 
and phragnymi , to enclose), a 
muscle characteristic of mam- 
