214 BRITISH TYROGLYPHIM. 







Megnin identifies this hypopus with Hypopus 

 feroniarum, Dufour, and Hypopus Dugesii, Claparede, 

 and this identification appears to have been taken for 

 granted by subsequent authors. In the case of 

 Claparede' s species I should say that it is certainly 

 correct ; that author's drawings and descriptions are 

 usually sufficient for identification ; but in the case of 

 Dufour's species I think the identity extremely 

 doubtful. It may possibly be correct, but I am not 

 able to see in Dufour's figure and description any 

 sufficient means of identifying a Hypopus, which is far 

 from being an easy matter ; the general shape, which 

 is the principal thing which can be judged of from 

 Dufour's figure, does not appear to me to agree well 

 with Megnin's rostro-serrdtum. 



Nymph. In this stage the creature has more the 

 form of the adult male than of the female, which is 

 unusual in the Acarina. The mammillary protuber- 

 ances on the dorsum are less developed than in the 

 adult ; there is not any sternum, the two epimera of 

 the first pair of legs being simply joined to each other 

 at their inner ends. The legs are thinner in proportion 

 than those of the adult. 



Larva resembles the nymph, except in the absence 

 of the fourth pair of legs. 



Eggs elliptical, about *16 mm. long and about '1 mm. 

 broad. 



Habitat. Megnin found the species originally 

 wading in great quantities in the thin film of liquid 

 which covers decaying mushrooms. It is hardly an 

 exaggeration to say that it may be found on all kinds 

 of damp, decaying, soft vegetation which has sub- 

 stantial thickness; it is perhaps most abundant on 

 fungi and roots, but it is very generally distributed ; 

 it is extremely abundant. The species has been 

 recorded in France, Germany, Italy, and Switzerland ; 

 it is found in all parts of England. It is, I think, a 

 follower, not an initiator of decay. 



