WILLIAMS: LARRID^ OF KANSAS. 135 



As has been remarked, the species just considered is a typi- 

 cal example of the family. In studying the various Larridse 

 it will be found that certain groups depart rather widely in a 

 number of anatomical points from the genus Tachytes. For 

 example, certain Larridse have three perfect ocelli, others lack 

 the pygidial area, while the shape of the head and thorax and 

 the neuration of the wings may differ to a considerable degree, 

 to say nothing of size. These various characters are noted in 

 the systematic portion of this paper, in the keys and generic 

 descriptions. 



