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X. Synopsis of British Hymenoptera. Diploptera and 

 Anthophila ; jj«?'^ /. to end of Andrenidae. By 

 Edwaed Saunders, F.L.S. 



[Kead May 3rd, 1882.] 



Plates VII.— XI. 



The Diploptera and Anthophila follow in natural order 

 after the Heterogi/na and Fossores, of which I gave a 

 synopsis of the British species in the volume of our 

 ' Transactions ' for 1880 (pp. 201—304). I have endea- 

 voured as much as possible to pursue the same method 

 with regard to the analytical tables and descriptions 

 in the Synopsis which I have now to lay before the 

 Society, so that the two together may form a complete 

 descriptive History of our British Aculeate Hymenoptera. 

 In the genera Halictus and Andrena I have had to 

 describe the species at some length, as they are often so 

 closely allied one to another that detailed descriptions 

 are almost a necessity, and for the same reason the 

 analytical tables in such cases are proportionately un- 

 satisfactory. I have, however, done my best to make 

 them as clear as possible ; and I feel sure that any one 

 who knows the difficulty of distinguishing between some 

 of the closely-allied species will not be surprised if in 

 some instances he has to refer to the detailed descrip- 

 tions, as well as to the tables, in order to name his insect 

 satisfactorily. 



Figures of the ^ genitalia (armature) have been given 

 of all the species possible in the genera, Colletes, Pro- 

 sopis, Halictus, &c. In Andrena, however, the characters 

 presented by these organs are not nearly so strongly 

 pronounced as in the allied genera, and I have therefore 

 not thought it worth while to figure them, except in such 

 instances where there is some striking divergence from 

 the ordinary type. 



The number of species in the Diploptera exceeds by 

 three that given by Mr. F. Smith in his 1871 Catalogue, 

 published by this Society ; whereas the Anthophila, to the 



TRANS. ENT. SOC. 1882. — PART II. (jULY.) 



