526 APHANIPTERA THYSANOPTERA chap. 



of the domestic fowl in Ceylon, and an allied form, Hhynehoj^sylla 

 jmlex, fastens itself to the eyelids and other parts of the body of 

 birds and bats in South America. In Turkestan VcrinijosT/lla 

 alakurt attacks cattle — ox, horse, camel, sheep — fastening itself to 

 the body of the animal after the fashion of a tick. Eetaining 

 this position all through the winter, it becomes distended some- 

 what after the manner of the Sand-flea, though it never forms 

 a spherical body. The parts of the mouth in this Insect (Fig. 251) 

 are unusually long, correlative with the thickness of the skins of 

 the animals on which it lives. Grassi considers that the dog's 

 flea, Pulex serraticeps, acts as the intermediate host of Taenia. 



Great difference of opinion has for long prevailed as to 

 whether fleas should be treated as a Sub-Order of Diptera or as 

 a separate Order of Insects. Wagner and Kiinckel, who have 

 recently discussed the question, think they may pass as aberrant 

 Diptera, while Packard,^ the last writer on the subject, prefers 

 to consider them a separate Order more closely allied to Diptera 

 than to any other Insects. Although widely known as Aphan- 

 iptera, several writers call them Siphonaptera, because Latreille 

 proposed that name for them some years before Kirby called 

 them Aphaniptera. Meinert considers them a separate Order 

 and calls it Suctoria, a most unfortunate name. 



Order VIII. Thysanoptera. 



SniaU Insects, with a jwl^ngerotis month 2)^i(ced on the iinder side of 

 the head and apposed to the sternum so ccs to he concealed. 

 With four slender wings, fringed loith long hairs on one or 

 loth margins, or with rudiments of vnngs, or entirely apterous. 

 Tarsi of one or two joints, terminated hy a vesicular structure. 

 The young resemble the adidt in general form, hut there is a 

 pupal stadium in tvhich the Insect is quiescent and takes no 

 food. 



The tiny Insects called Thrips are extremely abundant and 

 may often be found in profusion in flowers. Their size is only 

 from -glj to l^ of an inch in length ; those of the latter magni- 

 tude are in fact giant species, and so far as we know at present 

 are found only in Australia (Fig. 253). As regards the extent 

 ^ P. JJoston Soc. xxvi. 189-1, pp. 312-355. 



