CATALOGUE OF INSECTS. 13 



An offshoot from the order Diptera, which has become partly para- 

 sitic, we find in the fleas, for which the ordinal term Siphonoptera 

 is used. They are wingless, laterally compressed, and live as adults 

 on warm blooded, hair or fur coated animals. 



In a graphic form the scheme of classification and development is 

 shown on the accompanying diagram. (See page 14.) 



For convenience in cataloguing, the sequence of the orders is mod- 

 ified so that all the Neuropterous forms are grouped together, irre- 

 spective of the series to which they belong in point of development. 



