XXXVIU INTRODUCTION. 



b. Anterior legs inserted on the posterior 

 margin of prosternum. 



a. Rostrum free, three to four-jointed . . Notonectidae. 



b. Eostrum concealed, apparently un- 



jointed Corixidae. 



Two families of Heteroptera are not included in the above 

 synopsis. The fam. Aepophilidce is at present only represented by 

 a single Western Palsearctic species, and therefore need not claim 

 our attention. The Polyctenidcc include four or five species which 

 have been found parasitic on Bats. Westwood treated them as 

 aberrant Anoplura or Lice, while Dr. Sharp considers they should 

 be included in the Heteroptera ; but he adds that he has had no 

 opportunity of making a thorough examination of Polyctenes, and 

 therefore rightly speaks with some diffidence. 



EllHATUM. 



Page 395 top, for Cletus caluminator read Cletus calumniator. 



