388 ME. A. D. MICHAEL ON HTPOPI, 



with a view of ascertaining this soon led to the discovery of a 

 comparatively large, chitinous organ, below the brown shield- 

 shaped plate, which closely resembles the penis in many species 

 of Sarcoptidse parasitic on birds, as, for instance, Proctophyllodes 

 glandarinus, which are the very creatures where a similarity might 

 be expected to occur. I feel no doubt, therefore, that this is 

 the male ; but, from the varying position in which the inert larva 

 is held, I do not look upon the process as actual coition, but 

 rather as a holding possession with a view to coition immediately 

 the adult female should emerge, possibly before the chitinous 

 carapace had time to harden. I do not, in this, rely ou the 

 fact of the inert form being immature ; as in the above-named 

 case of P. glandarinus, and in other members of the Analginse 

 (Dermaleiehi), the male always copulates with a female which 

 has not undergone the last ecdysis nor assumed its final form. 



The inert larva, when it is dragged about by the male, generally 

 has the wholly or jDartly formed adult female showing plainly 

 through the semitransparent larval cuticle. 



I had observed that the cheese vanished slowly, even in those 

 cells which did not contain any cheese-mites, and that what I 

 will, for the moment, still call the Hypopi, for waut of a better 

 name, were very much about it. I therefore afterwards tried it in 

 breeding, and found that they throve well where it was. Utilizing 

 this, I placed some of those which I had just bred from the eggs 

 into a separate cell, and I succeeded in getting them to lay eggs, 

 and in rearing these eggs through their whole life-history, as I 

 had done in the first instance ; and this I rejDoated through several 

 generations, always with the same results, and without the 

 assistance of any bee or Ga?nasics. 



I have never seen either the larva or the male upon the bee 

 or the Gamasus, only the adult females ; this is not altogether 

 exceptional among Acarina, as in many Gramasidse the females 

 and nymphs are parasitic, either temporarily or permanently, 

 although the male never is so. 



I think that the above detailed experiments prove that this so- 

 called Hypopiis of the Gamasus of the humble-bee is a separate 

 adult species, fairly forming the type of a distinct genus. I 

 propose to call it " Disparipes homhi " *. 



* Decidedly tiie nearest ally is Kramer's l?ygme^horus : the rostrum, body, and 

 a large portion of the general arrangement is strikingly similar, but the great 

 difference in the fourth pair of legs, the absence in Pygmepkonis of the chiti- 



