On a curious insect from Brazil 1 ). 



The Secretary also exhibited a photograph on behalf of Dr. Fritz Miiller, 

 and read the following note: - 



"I take the liberty of sending you a photographic copy of some drawings 

 of a very curious dipterous insect. The larva is remarkable for having six seg- 

 ments only, each being provided on the ventral side with a complicated disk, by 

 which it firmly adheres to the rocks of rapids. The first segment of the larva 

 is a cephalothorax, comprising the head, thorax, and first abdominal segment of 

 the pupa. The pupa, which is firmly cemented to the rocks, has its antennae, 

 wings and legs free, not adherent to the body. The perfect insect is remarkable 

 for the dimorphism of the females. One set of females agrees in the want of 

 mandibulae and the structure of the oval parts with the males. They are probably 

 honey-sucking. The other set of females are provided with mandibulse, like the 

 blood-sucking females of Culex, Tab anus, &c. In the size of the eyes and the 

 structure of the feet the blood-sucking females differ much less from the males 

 than the honey-sucking females do. I have lately sent to the 'Archives do Museu 

 Nacional do Rio de Janeiro' a description of this insect, accompanied by seven 

 plates, three of which refer to the highly interesting structure of the larva." 



i) Trans. Ent. Soc. London 1879. Proc. p. L. 



