REVISION OF THE PARASITIC CHALCIDOID FLIES OF THE 

 GENERA HOMALOTYLUS ^lAYR AND ISODROMUS HOW- 

 ARD, WITH DESCRIPTIONS OF TWO CLOSELY RELATED 

 GENERA. 



By P. H. TiMBERLAKE, 



Of the Hawaiian Sugar Planters'' Association Experiment Station, Honolulu, Hawaii. 



The genus Homaloiylus was erected by Gustav Mayr * for three 

 European species which had been retained previously in Encyrtus^ 

 namely, E.fiarainius, vinulus, undjlaviceps — all described by Dalman 

 in 1820. A few months after Maj'-r's Vv^ork appeared, Thomson ^ 

 published his genus Nohrimus, based on the same three and a doubtful 

 fourth species, E. eytelweinU Ratzeburg, which Mayr had synonymized 

 with E.jlamini'us Dalman. Nohimiis has been considered a synonym 

 of Homaloi'ylus by subsequent writers, and Encyrius jiaminivs 

 Dalman is hereby definitely selected as the type, the same species 

 having been selected by Ashmead in 1900 as the type of Homalotylus* 

 The genus Mendozaniella Brethes ^ is unquestionably another syno- 

 nym of Homalotylus, as its type M. mirahilis Brethes, agrees through- 

 out in description and figure with the species of Homalohjlus belong- 

 ing to the Haminius group. The genus also has been redescribed by 

 Girault * under the name of Hemaenasoidea, the genotype species, 

 H. oculata, being closely allied to Homalotylus vicinus Silvestri. 



Of the eighteen species which have been described or subsequently 

 placed xmder Homalotylus only twelve rightfully belong here as the 

 genus is now restricted. //. vinulus (Dalman) and jlavicejjs (Dal- 

 man) belong to Isodromus Howard ; H. laclini Ashmead was referred 

 by its author to Pliaenodiscus in 1887,^ but in reality belongs to the 

 genus Microterys Thompson; H. similis Ashmead becomes the type 

 of the new genus, Anisotylus, Avhich the writer has ventured to sepa- 

 rate from Homalotylus, because of several peculiarities; H. hi^asciatus 

 Ashmead was removed by its author to MeromyzoUa in 1900; and 

 finally H. latipes Girault difters so profoundly in having scattered 

 pin-punctures on the body, foliate hind tibiae, and a three-jointed 

 club, that there is much doubt whether it has any close relationship 

 to Homalotylus at all. 



1 Verh. zool.-bot. Ges. Wien, vol. 25, Dec, 1875, or Jan., 1876, pp. 686, 752. 



2 Hymenoptera Scandinavia, vol. 4, 1876, pp. 116, 137. 



3 Anal. Mus. Nac. Buenos Aires, vol. 24, 1913, p. 97, fig. 7. 

 * Annals Entora. Soc. Amer., vol. 9, Sept., 1916, p. 307. 



6 Trans. Amer. Entom. Soc, vol. 14, p. 190. 



Proceedings U. S. National Museum, Vol. 56— No. 2293. 



