264 INTRODUCTION TO ZOOLOGY CHAP. 



mother tunnel, as shown in the diagram. In the enlargement 

 at the end of each secondary tunnel one larva pupates. It 

 emerges as a fully developed beetle the following spring, 

 leaving the tree by a fresh tunnel which it makes through the 

 bark. 



General Classification of Beetles mentioned in Chapter XVII. 



Order. COLEOPTERA. 



Sub- order 1. Adephaga. Predatory beetles with thread-like 



antennae, larvae active and predatory. 

 Family 1. Dytiscidae. 



Dyticus (or Dytiscus), the Carnivorous Water 



Beetle. 

 Acilius. 



Ilybius, the " Mud-dweller." 

 Family 2. Pelobiidae. The Screech Beetles. 

 Family 3. Cicindelidae. The Tiger Beetles. 

 Family 4. Carabidae. The Ground Beetles. 

 Sub -order 2. Clavicornia. Antennae usually thicker at the 



tip, though the thickening may be slight, 

 Family 1. Coccinellidae. Ladybirds. 

 Family 2. Staphylinidae. Cock-tail Beetles. 

 Family 3. Hydrophilidae. Silver Water Beetles. 

 Family 4. Gyrinidae. Whirligig Beetles. 

 Sub-order 3. Serricornia. Antennae usually serrate not a 



very coherent sub-order. 

 Family 1. Elateridae. Click Beetles. 

 Family 2. Lampyrides. Glow-worm Beetles. 

 Family 3. Ptinides. Furniture Beetles. 



Sub-order 4. Lamellicornia. The antennae have their last 

 joints enlarged to form horizontal leaf-like 

 parts. 



Family 1. Melolonthides. Cockchafers. 

 Family 2. Lucanidae. Stag Beetles. 



Sub -order 5. Rhynchophora (The Snout Beetles). The head 

 is prolonged in front to form a beak or "snout." 

 Family 1. Curculionidae. Weevils. 

 Family 2. Scolytidae. The Bark Beetles. 



PRACTICAL NOTES 



1. Get male and female specimens of Dyticus maryinalis and 

 keep them alone in a fairly large fresh-water tank with plenty of 



