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the Australian forms. The difficulties that I have encountered 

 may be realized by any one w'ho will examine the figures of 

 mandibles given by me and my descriptions of other structural 

 characters in the genera 'here described, and t'hen compare them 

 with the characters given in Ashmead's tables of tribes. Such 

 forms as Mcniscoccphalus and Fidgoriidcida, which 'have no trace 

 of a third mandibular tooth and would tberefore fall in the tribe 

 called Ectromini, have short stout mandibles, shorter and 

 stouter than in many tridentate species, and do not agree in 

 other characters with the Ectromini. Again such genera as 

 Echthrodryinus, EcJithmbaccha, and Ectopiognafha are difficult to 

 place, the apex of the mandibles being very different from the 

 ordinary tridentate form, and probably cannot be considered as 

 having more than two real teeth. The difficulty of seeing clear- 

 ly the mandibular structure is, as Ashmead observes, consider- 

 able, and no proper examination can be made in many species, 

 without either opening the jaws, or dissecting t'hem off. In all 

 the species here described except one, in which the mandibles 

 were opened, 'I have dissected off these appendages (generally 

 from several individuals of each genus) and examined them in 

 various positions as dry objects, as well as mounted in glycerine 

 and balsam. In Echfhrogouatopus, Hclegonafopus, Chalcerinys 

 and Chciloiicitnis they are nearly alike, and it was not necessary 

 to figure all these. All the figures were drawn under the high 

 magnification of about 240, excluding those of one or two of 

 the large species. The palpi furnish excellent characters in 

 some cases, but I have not been able to examine them in all 

 the genera. The posterior tibiae in Ncocladia have two distinct 

 c'alcaria. the shorter being easily visible with a lens. With the 

 possible exception of this genus, I believe all the other Encyr- 

 tinae here described s'hould be placed in Ashmead's tribe Mirini, 

 though, as stated, some have only two mandibular teeth, others 

 two more or less distinct ones and rudiments of one or even 

 two internal to these. Cameron has noted a rudimentary sec- 

 ond calcar on the posterior tibiae of one of tihe Mirini, and I 

 have observed a. very short one in one or two Australian species, 

 but not I think in any of those described in this paper. 



The other parasites present no difficulty as to the place they 

 should occupy. The genus Ootctrastichus comes in the tribe 

 Tetrastichini, amongst the genera that have no mesonotal 

 grooved line, but appears to be verv distinct from anv of these. 



