4 HYMEN OPT ERA 



after emerges a perfect Chrt/sis of the most brilliant colour, and 

 if it be a female indefatigable in activity. It is remarkable 

 that the larva of Chrysis is so much like that of Odynerus that 

 the two can only be distinguished externally by the colour, the 

 Odynerus Ijeing yellow and the Chrysis white ; but this is only 

 one of the many cases in which host and parasite are extremely 

 similar to the eye. Chrysis shunyhaipnsis has been reared from 

 the cocoons of a Lepidopterous Insect — Monona jiavesccns, family 

 Limacodidae — and it has been presumed that it eats the larva 

 therein contained. All other Chrysids, so far as known, live at 

 the expense of Hymenoptera (usually, as we have seen, actually 

 consuming their 1 todies), and it is not impossible that C. shany- 

 liaicnsis really lives on a Hymenopterous parasite in the cocoon 

 of the Lepidopteron. 



Parnvpcs carnea frequents the nests of Bemhex rostrata, a 

 solitary wasp that lias the unusual habit of bringing from time 

 to time a supply of food to its young larva ; for this purpose it 

 has to open the nest in which its young is enclosed, and the 

 Farnoiies takes advantage of this habit by entering the cell and 

 depositing there an egg which produces a larva that devours that 

 of the Bemhex. The species of the anomalous genus Clr2)fes live, 

 it is believed, at the expense of Tenthredinidae, and in all prob- 

 ability oviposit in their cocoons which are placed in the earth. 



Series 3. Hymenoptera Aculeata. 



21ie fenmlcs (^ivh ether icorkers or true females) provided tvith a 

 sting: trochanters usually 'undivided (monotrochous). Usually 

 fJie antennae of the males toith thirteen, of the females v:ith 

 twelve, joints {exeei?tions in ants numerous). 



These characters only define this series in a very unsatisfac- 

 tory manner, as no means of distinguishing the " sting " from the 

 homologous structures found in Tubulifera, and in the Procto- 

 trypid division of Hymenoptera Parasitica, have been pointed 

 out. As the structure of the trochanters is subject to numerous 

 exceptions, the classification at present existing is an arbitrary 

 one. It would probably be more satisfactory to separate the 

 Proctotrypidae (or a considerable part thereof) from the Para- 

 sitica, and unite them with the Tubulifera and Aculeata in 

 a great series, characterised by the fact that the ovipositor is 



