28 ENTOMOLOGICAL SOCIETY 



of Aphelininse and showed drawings of several of the speci- 

 mens. This material had come from Nawa, Compere, Green, 

 Lounsbury, Noack, Marlatt, and from others at Washington, 

 D. C. He stated that the aphelinine fauna of the District of 

 Columbia and all North America had been modified by the 

 imported species, which were parasitic upon the scale insects. 

 In many cases these had entirely replaced the native forms. 

 He stated that the commercial distribution of scale parasites 

 was first suggested by LeBaron in 1866. Although a number 

 of workers have spent considerable time upon these interesting 

 groups, there are still many undescribed species and genera. 

 Among the forms exhibited was Azotus, an interesting genus 

 which had been received from New Zealand ; Paris, France ; 

 Ohio, U. S. A. ; Cape of Good Hope ; and Bathurst, Australia. 

 Doctor Howard noted as of interest the finding in Mexico of 

 specimens of Foerster's Genus Mesidia. This was described 

 without type or species name by Foerster. 



At the conclusion of Doctor Howard's talk a discussion 

 came up regarding the question as to whether a genus must 

 have a described type. Dr. Stiles maintained that it was not 

 necessary, that the genus was mononomial and was valid even 

 if no species had been named with it. 



— Mr. Barber exhibited specimens of a peculiar fly which is 

 attracted in large numbers to the moist patches on the leaves 

 of the tree yucca at Hesperia, Cal., and presented the follow- 

 ing note in regard to it: 



NOTE ON OMOMYIA HIRSUTA COQUILLETT. 



(DIPTERA, PHYCODROMID.T..) 



By H. S. Barber. 



On May 12, 1903, I spent a short time trying to collect the 

 insects living on the tree yucca (Yucca arborescens) at Hes- 

 peria, Cal. Within a stone's throw of the railroad track and 

 nearly opposite where the train stopped stood a large yucca 

 that had recently died, having yellow leaves and slightly loos- 

 ened bark which came off, leaving the wood moist in places.^ 



* On the same tree were found the very strange lampyrid larvae prev- 

 iously described (Proc. Ent. Soc. Wash., Vol. vii, p. 117). 



