173 ©. R. Osten Sacken: 
Very interesting are the purely local tropical forms (Dapano- 
ptera, Peripheroptera, Libnotes) distinguished by an excessive de- 
velopment of secondary characters, without any change in the essen- 
tial ones; glaring instances of local adaptation to as yet unknown 
conditions of life. 
Dicranomyia. 
Stephens, Catal. of Brit. Ins. 1829; ©. Sacken, Monogr. of N. Am. 
Dipt. IV, p. 53, Tab. 1, f. 1-3, wing; tab. 3, f, 1A, forceps. 
(?) Ataracta Loew, Bernstein u. Bernsteinfauna 1850; ©. 8.1. c. 
pP 97; 
Spurious genus (?): Glochina Meigen, Syst. Beschr. VI, p. 280, 
Tab. 65, f. 7, 1830; Siagona on the plate. 
The empodia of this genus are described by me as indistinct 
or none; in some species however, for instance in D. morio they 
acquire some development. This character is more easy to study in 
living specimens than in dry ones. 
Diceranomyia seems to be more numerously represented in Europe 
than in North- America, probably owing to the greater moisture of 
the climate (as its larvae seem to live in the water). Many european 
species are as yet undescribed. The structure of the male forceps of 
most of them is characteristic, but must be studied on fresh speeimens 
I have figured some of these organs in Mon. etc. IV, Tab. 3, f. 1—4; 
and still earlier in the Stett. Ent. Z. 1854, Tab. 1 f. 3, 5, 6, 7; some 
of the latter have a very peculiar structure, and at that time, I took 
these species for Glochina Meig. Mr. Mik figured the forceps of 
the species from the Auckland Islands, described by him as well as 
of two european species, D. trinotata M. and dumetorum M. (Verh. 
7. B. Ges. 1881, Tab. 1e.tie. 2.2.3, 9,06, 7). 
Very few exotice Diceranomytae have been described. Those 
from temperate climates generally reproduce the characters of 
european species (for instance the species from New-Zealand, or those 
from the Auckland Islands). However I possess an undescribed 
species from New-Zealand (D. monilicornis of my collection) which 
in the male sex, has distinetly moniliform antennae, like a female 
Fhipidia; the rostrum and proboseis are a little longer than the 
head, somewhat like those of the north-american D. rostrifera. Mo- 
reover it has scattered erect hairs on the legs, quite unnsual among 
Dieranomyiae. 
Of exotie Dieranomyiae from tropical regions only a single 
one has been described, D. saltans Dolesch. from Java, which I 
have also received from the Philippine Islands (0. S. Berl. Ent. Z. 
