304 ME. A. D. MICHAEL ON THE 



After tlie first nymphal change of skin, the specimens showed 

 the strongly divided dorsal plates, and were in eveiy respect similar 

 to the first pair when originally captured. 



On 27th May the first adults appeared ; they were of course 

 precisely like those they were bred from, did not show any divi- 

 sion of the dorsal plate, and never became hard and chitinous, but 

 remained of a leathery texture. 



Third Generation. — The adults bred on the 27th May again laid 

 eggs, and I bred them through a third generation with similar 

 results, which, therefore, I do not detail. 



It now remained to show for certain that these actually were 

 the same species as that parasitic upon the beetle; I there- 

 fore, on 18th July, 1880, captured a beetle ( Geotrupes stercorarius) 

 with a large number of coleoptratorum upon it. The closest 

 examination did not show any difference between these and those 

 bred before. I removed them from the beetle and established 

 them in several cells. They throve just as well as those captured in 

 the open, an interesting circumstance, because Duges* says, with 

 reference to them : — " It is to be noticed that almost all Gamasids 

 dry up and die in a few hours after being separated from the 

 insect or stone unless they are kept in a damp vase ;" and Andrew 

 Murrayt repeats this as " a peculiarity of all these parasites on 

 insects." The real fact is that they thrive on precisely the same 

 treatment as those not captured on insects or under stones, and 

 do not require as much moisture as many other non-parasitic 

 Acari, as, for instance, some of the Oribatidse, which never are 

 parasitic in any stages. Probably Duges did not supply them 

 with proper food. 



From the 1st to the 5th August most of those captured on the 

 beetle became adulfc. 



On 5th August I put an adult male and female of this lot into 

 a small cell together. 



On the 9th there was an egg in this cell* which I removed and 

 put in a cell by itself. 



On the 11th this egg hatched, and produced a hexapod 

 larva. 



On the 14th this larva changed into the nymphal stage. 



On the 19th it underwent ecdysis and became a mature nymphs 



w Loc. tit. p. 26i 



t ' Economic Entomology,' p. 158. 



