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jecture, as it was when Westwood wrote his "Introduction." On 

 examination of the AustraHan Stylopidae that infest Jassids, it 

 is evident that these are so extremely close to Halictophagus 

 as figured by Westwood that I have left one of these species in 

 that genus and have made a new subgenus for the reception of 

 another. I incline to believe that Halictophagus, which appears 

 to be very little known, and hardly noticed since J. C. Dale cap- 

 tured the type of the genus in 1832, and again took it in the 

 same county (Dorset) in England in i8>40j_ is really a Jassid 

 parasite, and could be easily bred in numbers by any one who 

 would investigate some of the Jassids in that country, Agallia, 

 Tcttigonia, or some such common form, being likely to prove its 

 hosts. I am further led to believe its connection with Halictus 

 is entirely suppositions because Mr. C. W. Dale, the son of the 

 above named entomologist, writing 60 years after the type was 

 obtained, says "Halictophagus is supposed to be a parasite of 

 Halictus, Elcnchus of Prosopis." We know the latter assign- 

 ment of host and parasite to be incorrect, and probably the 

 former is also. The Australian species of Halictophagus and of 

 vvhich males are known are confined to Jassids, but females of 

 a quite distinct species found on large Fulgorids are in my opin- 

 ion also allied, and belong to the same group. 



The genus Elcnchus. 



So far as our observations have gone, these being- confined 

 to a single species, Elcnchus attacks only .Delphacid leaf- 

 hoppers, and of these only such as feed on Graminaceous plants, 

 not those found on shrubs or trees. I see no reason, after the 

 examination of dry and alcoholic material and specimens pre- 

 served in balsam, to specifically separate the Australian exam- 

 ples from the American (the latter from Ohio and California^ 

 nor either of these from the Vitian. Again 1 refer all these to 

 the British Elcnchus tcnuicornis. Other species of Elcnchus 

 have been described from Mauritius and Britain, but whether 

 these are all distinct, I feel some doubts. Dried specimens of 

 these insects become more or less distorted or shrivelled, so 

 that examples of one species thou,'gh taken together often ex- 

 hibit apparent differences from these causes. Mounted in bal- 

 sam, sHght differences in position often give a very different 

 appearance to various structures, e. g., the antennae, genitalia, 

 etc. Next to fresh specimens those preserved in alcohol are 

 most suitable for study. Throughout Koebele's notes this 

 species is referred to under the name Colacina Westw. on the 



