THE PHYLOGENY OF THE NEMOCERA, WITH NOTES 



ON THE LEG BRISTLES, HAIRS AND CERTAIN 



MOUTH GLANDS OF DIPTERA. 1 



W. WESCHE, F.R.M.S. 



Professor Williston has published a paper 2 on the antennae of 

 Diptera which is not only a remai kable analysis of these organs, 

 but one showing an encyclopaedic knowledge. His deductions 

 combined with his observations on other characters seem to me 

 of great weight and importance, and may lead to a more exact 

 classification of the order. 



On page 326 of the cited paper, in commenting on the number 

 of antennal joints in the different families of Diptera, he says: 

 ' We are at once struck with the predominance of five groups 

 having a maximum normal number of sixteen, fifteen, ten, six 

 and five. And I venture to suggest that these five groups repre- 

 sent in the main five different divergent phyla of Diptera." 

 These groups are: 



Group i. Families having from twelve to sixteen joints: 

 Tipulidae, Cecidomyidse, Psychodidae, Mycetophilidae, Pachy- 

 neurinae, Rhyphidae. 



Group 2.- Families with from six to fifteen joints: Dixidae, 

 Culicidae, Blepharoceridae, Chironomidae. 



Group j. Families with from seven to ten joints: Scatopsinae, 

 Simulidae, Xylophaginae, Stratiomyidae, Acanthomeridae, Taban- 

 idae. 



Group 4. Families with from three to six joints : Nemistrinidae, 

 Lonchopteridae, Phoridae, Cyclorrhapha. 



1 The MS. of the present article was sent to me some time before his death by 

 the late Mr. Wesche, with a request for comment and criticisms. In editing the 

 paper, which Mr. Wesche had not quite completed, I have made no changes what- 

 ever except verbal ones, and have omitted only a few immaterial parts. Most of 

 his conclusions seem well taken, and it is to be regretted that the author could 

 not have been spared to continue his researches along the fruitful lines that he 

 had begun. S. W. WILLISTON. 



2 BIOLOGICAL BULLETIN, XIII., p. 324, 1907. 



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