528 ANIMAL SUBSTANCES 



(6) Lepidoptera. Butterflies and moths ; they have four scaly 

 wings, a suctorial mouth, and no ovipositor. 



(c) Diptera. House-flies, gnats, midges, &c. ; they have one 



pair of transparent wings and a suctorial mouth ; the 

 larva is a maggot. 



(d) Coleoptera. Beetles ; these have one pair of wings and one 



pair of hardened wing-cases ; they are provided with 

 biting mandibles. 



All the members of the foregoing orders undergo a complete meta- 

 morphosis from larva to perfect insect. 



(e) Hemiptera. Aphides, Coccus insects, bugs, &c. ; these 



have piercing, suctorial mouths and either two pairs of 

 wings or none (the male Coccus insect alone undergoes 

 complete metamorphosis) . 



The Arachnoidea include the scorpions, spiders, mites, ticks, &c. 



Phylum X. Mollusca. The Molluscs (snails, mussels, oysters, 

 cuttlefishes, &c.) are unsegmented, have no appendages, and have a 

 soft body secreting an outer shell (in the cuttlefish an inner, calcareous 

 shell). 



Phylum XL Chordata (Verlebrata). These have a dorsal 

 supporting axis and a dorsal, tubular nervous system. The most 

 important classes are the Pisces, the Amphibia, the Reptilia, the 

 Aves, and the Mammalia. 



The chief sub-classes of the Pisces are (i) Elasmobranchii or 

 Cartilaginous Fishes such as the skate, shark, dog-fish, &c., and (ii) 

 Teleostomi, which have a more or less bony skeleton. The most 

 important order of Teleostomi is Teleostei, or true Bony Fishes, which 

 includes the cod, herring, salmon, and most of the modern fishes. 



The class Amphibia are those vertebrates which exhibit a transition 

 from aquatic to terrestrial life. The frog, toad, and newt are types. 



The class Reptilia includes the tortoises, turtles, lizards, snakes, 

 alligators, &c. 



The class Aves includes the divisions Eatitce or Running Birds 

 (ostrich) and the Carinatce or Flying Birds. 



Of the class Mammalia the following Orders belonging to Sub-class 

 Eutheria or placenta! animals may be mentioned : (i) Xenarthra 

 (sloths, anteaters) ; (ii) Nomarthra (pangolins) ; (iii) Sirenia (dugong, 

 sea-cow) ; (iv) Ungulata (hoofed animals such as the ox, hog, sheep, 

 musk-deer, &c.) ; (v) Cetacea (whales, dolphins, &c.) ; (vi) Eodentia 

 (rats, beavers, &c.) ; (vii), Carnivora (lions, tigers, bears, &c.) ; (viii) 

 Pinnipedia (seals, walruses) ; (ix) Insectivora (hedgehogs, shrews, 

 &c.) ; (x) Chiroptera (bats) ; (xi) Prosimios (lemurs) : (xii) Anthropoidea 

 (monkeys, baboons, apes, man). 



