420 Osten Sacken: on the characters ofthe three divisions of 



organized families.i) On p. 24 of the same work he defincs these 

 two divisions, like Latreille, by the two characters borrowed from 

 the antennae and palpi: 



Antennae at least six-jointed; palpi four- er five-jointed. 



Nemocera. 

 Antennae three-jointed; palpi one er two-jointed. 



Brachycera. 



For some unexplained reason later authors have neglected the 

 character borrowed from the palpi, and have concentrated their atten- 

 tion on the antennae. None of them seem to have realized that we 

 niay separate the two divisions on account of the palpi alone, without 

 regard to the antennae/^) 



Meigen, in his definition of the Nemocera (his Tipulidae, Syst. 

 Beschr. Vol. I, p. XXIII, 1818) does not even State the nuniber of 

 the joints of the palpi („Taster vorstehend, gegliedert"). The other 

 authors copy the Statement about the palpi from Latreille and from 

 each other in a sort of perfunctory s) manner, without seeming to 

 realize the importance of this character (Zetterstedt, Dipt. Scand. I, 

 p.68; Schiner, Fauna etc. I, p. XXXVII; Brauer, Z. K. M, I, p. 7 

 and 9). Haliday alone, in Walker's Ins, Brit. Dipt. I, p. 5 makes 

 an independent Statement, and comes nearer a true appreciation : 

 „Nemocera^ palpi plerumque deflexi, articulis pluribus exsertis; 

 Brachycera, palpi porrecti, aut proboscidi incumbentes, quasi ex- 

 articulati. " 



The consequence of this neglect of the palpi was that when the 

 genus Rhachicerus was discovered, this discovery induced entomo- 

 logists to pay more attention to other forms of Brachycera with 



i) For this reason the remark of Brauer (Z. K. M. II, p. 42, 1882): 

 „Seit der verfehlten Eintheilung der Dipteren in Nemocera und 

 Brachycera durch Macquart" etc. is incorrect, and the failure is 

 entirely on Brauer's side. 



2) It is Strange that Latreille, in his later work: „FamilJes naturelles 

 etc." (1825) for some reason did not use the character borrowed from 

 the palpi; I mean to say that, in characterizing the two divisions, he 

 has mentioned the antennae only (compare I. c. p. 482 and 486, both 

 at the top). As this work of Latreille was the principal one used by 

 later authors, it may be that the probably accidental Omission of the 

 palpi by Latreille himself has prevented his successors from grasping 

 the importance of this character. 



s) Perfunctory in Webster's dictionary isdefined: „Done without 

 interest or zeal, and merely lo get rid of a duty ; performed mecharii- 

 cally, as a thing of rote." This is exactly the meaning I intended to 

 convey. 



