WORK IN EUROPE 
13 
thoracic squamae, which do not exist in the Xemocera , etc. The 
larvae belong to a peculiar type, called the long-headed larvae 
(Marno). 
An important feature of my superfamily Eremochaeta is the 
suppression of the old-fashioned family Xylophagidae. I showed 
that, from the very beginning, it was founded on the erroneous 
notion of a close affinity between the genera Xylophagus and Su- 
hula. It was a spurious family, not founded on any distinctly 
defined concept, and therefore a stumbling-block for a future de¬ 
velopment of the classification. Routine, and nothing else, had 
kept up this arrangement so long. When I found it reproduced 
in Brauer’s paper on the Notacantha (1882), I took occasion to state 
my objections in the Berl. Ent. Zeit., 1882, p. 364-366, 89 (1882), 
where a detailed historical statement is given. The components of 
the old-fashioned Xylophagidae (including, probably, even Chiro- 
myza') must be absorbed in an enlarged concept of the family 
Leptidae. Since the discovery of many transitional forms in 
Xortli America, Chili, and Australia, such a result is unavoidable, 
although a great deal remains yet to be cleared up. 1 
In continuing my researches after 1892, I proposed, five years 
later in the Berl. Ent. Zeit., 1897, the introduction of three new su- 
perfamilies to complete the subdivision of the Orthorrhapha Bra- 
chycera, 158 (1897). My new scheme was principally founded upon 
the contrast between aerial and pedestrian Diptera, a contrast the 
chief features of which had been already foreshadowed by me in my 
Essay on Chaetotaxy (102 (1884), p. 500-501), and to which I 
have given a further development in the above-quoted paper in the 
Berl. Ent. Zeit., 1897, p. 366—367. In the present “ Record,” Part 
II, Chapter XXIV, I have given an elaborate essay on the influence 
of the two modes of life-habit on the organization of all the families 
of Diptera. Besides the superfamily (1) Eremochaeta , adopted by 
me in 1892, the three new ones, introduced in 1897, were (2) 
Mydaidae , for this single family, which I consider as a relic of an 
1 I cannot, of course, reproduce here the numerous innovations introduced in my 
130 (1892), for instance in the grouping of the families within the superfamily Nemo- 
cera vent, and must refer the reader to the paper itself, or to the account of it given in 
the “ List.” 
