ART. 20. 



STUDIES OF THE BITING LICE — EWING. 



35 



Mallophaga. This is because of its apparent restriction to a single 

 zoogeograpliical region, while its evident host distribution is on large 

 taxononiic groups that have almost a worldwide distribution.' 



Fig. 18. — Chart showing thb geographical distribution of the (iYRorinAK. 



GEOGRAPHICAL DISTRIBUTION. 



If we except a single record from Europe, all others, that are from 

 hosts existing in a state of nature, come from the neotropical region. 

 The extent of the distribution of the Gyropidae is indicated by the 

 accompanying map (fig. 18), which shows records as far south as 

 southern Aigentina and as far north as Nicaragua, as far west as 



