692 DERMATINA 



Mydaidm are allied to the Apioceridm, and by this means the connecting 

 Hnks can be traced. The Dermatina are easily distinguished from the 

 EREMOCHiETA by the presence of only two pad-like pulvilli; from the 

 Teomoptera by their heavily built pedestrian legs, distinct venation and 

 antennae, their dichoptic heads, and their general absence of any furry 

 pubescence; and from the Energopoda by their distinct venation 

 (except in rare cases) and anteiinse, and by the absence of any chaetotactic 

 bristles. They include only two small families, which at first sight seem 

 to have but little in common, the best known Mydaidm being gigantic 

 flies of American origin endowed with a peculiarly complex venation, 

 while the Scenopinidce are small flies which occur in houses and have a 

 very simple venation ; a study of exotic forms however produces some 

 connecting links, and Brauer in his exhaustive inquiry into the relation- 

 ship of Sceno2nnus stated that the Mydaidce with short antennae show the 

 most undoubted (unzweifelhaftesten) connection with Sccnopinus. Osten 

 Sacken gave super-family rank to the Mydaidm alone, and apparently 

 reluctantly left the Scenopinidm along with the Therevidce " according to 

 " the received opinion," 



The larvae as far as is known are parasitic or predaceous. The name 

 of the super-family is derived from Sep/narivog, denoting "the leathery 

 " ones." I am aware that there is a genus of Hemiptera called Dermatinus, 

 but I agree with Osten Sacken's views (Entom. Mon. Mag., xxix., 149) 

 that the appellations of these larger groups are " not exactly names but 

 " designations" and as such are not subject to the laws of generic 

 nomenclature. 



