1889.] 



THE YOUNG NATURALIST. 



191 



Simulidae and Rhyphidae, which will give a fair idea of the naming, 

 or misnaming, of the whole collection. 



The family Simulidse contains but one genus, Simulum. Accord- 

 ing to the British Museum collection there are eighteen species of 

 this genus, viz. : — ornatum, reptans, varium, variegatum, affinis, leutecornis, 

 picipes, flavipes, elegans, lineatum, marginatum, auricoma, latipes, nigrum, 

 cinctum, equina, sericatum, and rufipes. In Mr. Walker's 11 Insecta 

 Britannica " (Diptera, Vol. III.), he gives the following as the British 

 representatives : — reptans, elegans, marginata, lineata, and fuscipes. In 

 the latest list of British Diptera (1888), by Mr. G. H. Verrall, reptans 

 and maculatum are the only two species of this genus recorded as 

 undoubtedly British. 



The family Rhyphidae is comprised in one genus. In the British 

 Museum the species named are : — fuscatus, fenestvalis, punctatus, and 

 variegatus. Walker (Diptera, Vol. III.) describes R. nigricans and 

 cinctus. In Mr. Verrall's list the species set forth as British are : — ■ 

 R.fenetralis and punctatus ; cinctus is regarded as doubtful. 



I have selected the foregoing as a sample only of the difficulties 

 which students have to contend with, when endeavouring to decide 

 species by comparison with the named specimens at S. Kensington. 



Seeing that so many of the British Diptera are misnamed, it 

 would be highly beneficial to the future students of this order, if some 

 one who has studied the British forms would volunteer to re-arrange 

 and re-name the specimens in this collection ; and there is no doubt 

 that the British Museum authorities, would be only too glad to 

 afford every facility to any person who might be disposed to under- 

 take the task. 



10, Kingsland Green, Dalston, N.E. 



On the Wings of Insects. 



By CHAS. H. H. WALKER. 



(Continued from page 142.) 



I have experimentally confirmed this theory of the stridulation of 

 the cricket, if, indeed, we can call anything a theory in which the 

 functions of the various parts are as self-assertive. By removing the 

 tegmina from a dead cricket, and holding them in such a manner that 

 the above conditions are fulfilled, then a rapid frictional movement 

 will give a faint squeak, yet sufficiently loud to be heard in any part of 



