320 AN INTRODUCTION TO THE STUDY OF FOSSILS 



38. Paleohemiptera (Permian to Jurassic). 39. Hemiptera 

 (Jurassic to present). Bugs. 40, Homoptera (Jurassic to 

 present) ; e.g. plant lice, harvest-flies. 41. Aptera (Oligocene 

 to present). Spring- tails. This is often separated into four 

 orders. 



1. Why are insects classed within the phylum Arthropoda? 



2. What characterizes an insect ? 



3. In what respects are the eyes of most insects like those of 

 most trilobites ? 



4. Account for the fossil preservation of the delicate veining 

 in the wings of insects. 



5. How does an insect breathe? How does this differ from 

 the respiration of a vertebrate ? 



6. What is meant by metamorphosis ? 



7. Outline the development of the house fly. 



8. Name some localities famous for the preservation of such 

 delicate bodies as those of the Insecta and Arachnida. 



9. What is meant by the generalized structure of the early 

 insects ? 



10. Name some orders of insects, giving under each the geo- 

 logic range and a living example. 



1. What characters distinguish the Arthropoda from other 

 phyla ? 



2. Give some characters which place them at the top of all 

 invertebrate animals. 



3. How long geologically has this phylum been in existence? 



4. How do you account for the earlier existence of water- 

 dwelling than of open-air-dwelling arthropods ? 



5. Define Arthropoda, illustrating your definition with 

 examples. 



6. How do the Arthropoda differ from the Annulata in the 

 following characters : (a) habitat, (b) protecting and supporting 

 skeleton, (c) locomotion, (d) food, (e) its capture, (/) its intake, 

 ig) digestion, (k) blood circulation, (/) excretion of waste, (J) res- 

 piration, (k) nervous system, (/) sense organs, (w) reproduc- 

 tion, (n) geologic range. 



7. How do the members of the larger divisions of this phylum 

 avoid competition in food getting ? 



