1918] Thoracic Sclerites of Ilcniiptera 247 



It will be seen that these resuhs are not entirely in harmony 

 with the conclusions of certain writers (Osborn, 1S9G; Kirkaldy, 

 19()S, 1909; Handlirsch, 1906-'()S; Renter, 1910), concerning the 

 phylogeny of the Hemiptera. This, of course, is to be expected, 

 since the grouping above is based entirely on the morphology of 

 the thorax. Handlirsch, 190G-'08, places the Aleyrodidae near 

 the Fulgoridas, and though superficially the two families do not 

 seem related, the thoracic sclerites support this grouping. The 

 arrangement of other Homopterous families followed by writers 

 on phylogeny is not generally borne out by the morphology of 

 the thorax. 



The Notonectidse, Corixid£e, Belostomatidae and Nepidae are 

 placed together by Osborn, 189G, Handlirsch, 1906-'08, and 

 Renter, 1910, but Kirkaldy, 1908, 1909, separates the Nepid« 

 from the others. Both Handlirsch, 1906-'08, and Renter, 1910. 

 place the Capsidae, Cimicidae and Nabidse fairly near each 

 other, and this arrangement agrees with their thoracic structure. 

 The close connection of the Reduviidas and Phymatidas is shown 

 by Kirkaldy, 1908, 1909, HandHrsch, 1906-'08, and Renter, 

 1910. The Pentatomid£e, Scutelleridae and Corymelaenidae are 

 usually placed together by writers on phylogeny. 



It will thus be seen that relationships shown by the thoracic 

 sclerites are supported in part by the conclusions of writers on 

 phylogeny, especially Handlirsch and Renter. In the relation- 

 ships of the Homopterous families, of the Coreidae, Lygaeidae 

 and Tingitidae, and of the Berytidae, Gerridas and Emesidse the 

 results obtained in this study do not agree with those of the 

 writers mentioned. More extensive and thorough study of 

 other morphological features as well as of the thorax mil be 

 necessar>^ to show the true relationships of these groups. 



