o52 C. R. Osten Sacketi: 



reiTiark that my Jirticle in the Berl. Zeitsch. had no other purpose 

 than a critical revicw of the existing literature. With a stock-in- 

 trade of two Liponeurae only (as I stated on p. 150, line 11 from 

 bottoni), I could not attempt new discoveries. C. R. Osten Sacken, 

 Heidelberg April 1, 1895." 



With Prof, Mik's permission, I reproduce a portion of his letter, 

 dated March 15, 1895. Although, as he says, its conclusions are not 

 always final for want of fresh specimens, it will be fonnd very sug- 

 gestive of future research, and for this reason I prefer to give it 

 verbat im. 



[Translation.] „When Loew said about Blepharocera (Revi- 

 sion etc. 1877, p. 64, lines 15 and IG from top) 'antennae without 

 any longcr hairs' he was in error (the same mistake is repeated on 

 p. 83 for the whole Famil}'). The antennae must be examined under 

 the Compound microscope. Even a power of 40 sliows Single longer 

 hairs, besides the dense, short pubescence Besidcs these, the front 

 side of the antennae, especially towards the tip, shows hairs which 

 almost resemble a beard; the antennae, under that power appear 

 densely ciliated! Loew is likewise in error when (1877, p. 66, line 5 

 from top) he says: 'Bleph. and Lipon, have an entirely similar 

 strncture of the antennae'. I examined females of both genera and 

 must say that, as regards the antennae, Bleph. is totally diiferent 

 from Liponeura. Blepharocera has cylindrical joints, in Liponeura 

 the joints are swoUen in the middle, so that the antennae of the 

 first may be called setaccous, while those of Lipon., at least under 

 a weak magnifying power, are almost moiiiliform, especially in Lip. 

 hrevirostris. In Bleph. Q the joints are much longer. The beard 

 on the antennae of Bleph. 5 I have described above. In Lip. Q 

 the dense, short pubescence is quite uniform, not ciliated, or bearded 

 on the front part of the joints; some stray longei- hairs also appear 

 on all the joints in Bleph. arocera, and, although very much 

 scattered, they show some regularity of distribution on the Single 

 joints. Lipon, is moreover provided on joints 1 and 2 on the under- 

 side, with some hairs, like cilia. which do not seem lo exist in 

 Bleph. — In Bleph. fasciaia Q I have discovered under the base 

 of each of the antennae, somewhat on the outer side, a tubercle 

 bcset at the tip with rather long bristle-like hairs, diverging like 

 rays. This character, as far as I know, has never been noticed by 

 any author. My tliree male specimens, unfortunabely very badly 

 preserved, do not show thesc tubercles, at least I cannot see them. 

 The antennae of Blepharocera male, are shorter than in tlio fomale, 

 and, as far as I can see, also moniliform; the joints are much 



