On the Parasitism o/*Rhi]Mpliorus paradoxus. 191 



II. Micropcreuta. 



Stoinacli-walhvitli sim- 

 ple cutaneous pores 

 (interstices in the 

 parenchyma), with- 

 out pjirietal canals. 



III. Orthoporeuta. 



Stomach-wall with 

 straiglit, regular, ra- 

 dial parietal canals. 



A stock with 

 many 

 mouth- 

 openings. 



One person with one mouth-open- 

 ing 2. Ohjnthida. 



Persons developed, 

 all with mouth- 



I oponings 5. Soleniscida. 



i Person," rudimen- 

 tary, many with- 

 out mouth-optni- 



ing G. Tarromida. 



A stock with one mouth-opening '.). Xftrdopsida. 

 A person without mouth-opening 11. Histohinthida. 

 A stock without mouth-opening... 14. Hycorrhizida. 

 A stock composed of persons and 



stocks of diverse genera 17. Thecometrida. 



One person with one mouth-open- 

 ing 3. Sycarida. 



A stock with many mouth-open- 

 ings ••••• •••• 



A person without a mouth-opening 



A .•?tock without mouth-openings . 



A stof^k composed of persons and 

 stocks of different genera 



One person with one mouth-open- 



7. Si/codendrUla. 



12. Sycocysfida. 



15. Sycophyllida. 



18. Sycometrida. 



rV. Cladoporeuta. 



Stomach -wall with 

 crooked, irregular, 

 branched parietal 

 canals. 



ing 4. Dyssycida. 



A stock with many mouth-open- 

 ings 



A stock with one mouth-opening . 



One person without mouth-open- 

 ing 



A stock without mouth-openings . 



8. Sycothamnida. 



10. Ccenostomida. 



13. Lipostomida. 



16. Sycolf'pida. 



XIX. — On the Parasitism o/" Rhipipliorus paradoxus. 

 By T. Algekxon Chapman, M.I). 



I HAVE read Mr, Murray's papers on the economy of Rhipi- 

 ^^o?-?/s with much interest; and although he has not succeeded 

 in converting me to his views of its life-history, he has added 

 to our knowledge of its habits and raised anew an interest in 

 the relations subsisting between the wasps and their parasites 

 which will probably lead to observations in the coming season 

 that will set at rest many of the points in dispute. 



In the meantime I think it very desirable to form as correct 

 an hypothesis of the life oi lihipiphorus as our facts admit of, 

 since an approximation to the truth is a most valuable guide 

 in making fiuther investigations, while, on the contraiy, an 

 erroneous theoiy may blind us to very obvious truths. 



I cannot better begin the remarks I desire to make than l)y 

 rendering Avhat appears to me to be but justice to the accuracy 

 of the earliest record we have of the economy oi Phipiphorus^ 

 meagre and deficient in detail though this record is. The ob- 

 sei-vations of Mr.Denison, brought to our notice by Mr. Smith 

 from the papers of the Ashmolean Society, appear to me to 



