JOUENAL 



OF THE 



ROYAL MICROSCOPICAL SOCIETY. 



AUGUST, 1908. 



TRANSACTIONS OF THE SOCIETY. 



XII. — On the Microscope as an Aid to the Study of Biology in 

 Entomology, with particular reference to the Food of Insects. 



By W. Wesche, F.E.M.S. 



(Read January 15, 1908.) 

 Plates V. to X. 



Entomologists are generally satisfied with the identification and 

 classification of their specimens ; connected with this work are many 

 points of the greatest interest, such as variation and mimicry, and 

 in the phylogeny new points are constantly arising and give little 

 leisure for other work. So the large majority of the life-histories 

 still remain unstudied, and the habits of many well known species 



EXPLANATION OF PLATE V. 



Fig. 1. — Fore leg of Chrysops arcutiens L. $ . To illustrate the simple type 

 of limb. This insect belongs to the family of the Tabanidse, and is a well known 

 and keen blood-sucker. It is met with in our English woods and meadows. 



Fig. 2. — Middle leg of Chrysopilns aureus Mg. 9 . Simple type. Belongs to 

 the Leptidse, and is not uncommon in long grass and meadows. 



Fig. 3. — Hind leg of Beris vallata Forst. 9 . Simple type. Belongs to the 

 Stratiomyidse ; is very common, and found on the hedges. 



Fig. 4. — Fore leg of Hydroplwrus ; species undetermined (c$). To illustrate 

 the raptorial or predaceous type. Belongs to the Dolichopodidse, and resembles 

 Aphrosylus in the structure of the legs, but has dissimilar mouth-parts. It is a 

 small Australian insect, which I captured at Geelong, Vic. 



Fig. 5. — Fore leg of Notiphila cinerea Fin. 9 . Raptorial type. It has the 

 remarkable saw-like process on the femur, found also in many of the Hydrellinse. 

 It is placed in the Ephydridse, is an inhabitant of damp places, and is rare in my 

 experience. 



Fig. 6. — Middle leg of Caricea tigrina F. $ . Raptorial type. Placed in the 

 Anthomyidae, but is fiercely predaceous. Common in damp meadows. 



Aug. 19th, 1908 2 e 



