29G [DccenilDcr, 



cacity ("ihreii Scharfsiiin "),in unravelling some of Walker's species 

 of the latter group. I find my identifications (which Loew accepted) 

 enumerated in a letter of mine of October 9th, 1874, of which 1 

 reproduce the corresponding passage : " The species of Dasj/pogon 

 which you left to my perspicacity to determine I have subjected to a 

 critical scrutiny. Dnsyp. ritfescens, Macq., is very probably Diogmites 

 discolor, Lw. ; Macquart has overlooked the spurs of the front tibise. 

 D. Fnlto, AV^alk., is Cyrtopogon chrysopogon, Loew ; in Walker's 

 description you must read face for front. D. Macerinus, Wk., 

 wretchedly described, seems to be your Aiiisopogon gibhus. Finally, 

 D. Liitntius, Wk., is the species which, in my last invoice, T sent you 

 under No. 45S, &c. This last species is introduced into my Catahigue 

 of 187S, p. G9, as Cyrtopogon Lufatms, Walk. ; the other species will 

 be found in their places as probable synonyms of Loew's correspond- 

 ing species." 



The faculty of visualization is quite indispensable for a respon- 

 sible entomologist to possess, and it would be expedient, I think, to 

 examine aspirants for appointments in Museums in regard to it, just 

 as candidates for railway-service are examined for colour-vision. 

 Heidelberg : September 12th, 1901. 



MOSQUITO SWARMS EESPONSIVE TO SOUNDS. 

 BY C. R. OSTEN SACKEN. 



A communication from Jamaica, published in " Nature," October 

 17th, p. 607, about mosquitos being " responsive to certain sounds, 

 such as a continuous whoop or hum," reminds me of a somewhat 

 similar communication which I received from a naturalist in Cuba 

 during my visit there in 1858. 



While standing in the midst of a swarm of mosquitos, and 

 listening to the sound of some musical instrument in the vicinity, it 

 has been noticed that each time w^hen the note A {la) resounds, the 

 swarm is pervaded by a tremor which the listener remarks through a 

 number of mosquitos coming in simultaneous and momentary contact 

 with his head. 



Although I have not had occasion to verify this observation 

 myself, I published a short notice of it in the " Stettiner Entomolo- 

 gische Zeitung," 18GI, p. 52, under the heading, " Miickenschwarme 

 and Musik." 



Heidelberg, Germany : 



INovemher 2nd, 1901. 



