A. D. MICHAEL ON TWO SPECIES OF ACARINA. 115 



Hypopus question, I do not now propose to express any opinion as 

 to what an Hypoima is, but I simply record the fact that I also 

 found Kramer's Lahidophorus talpce accompanying his Pygme- 

 phorus spinosus, and I did not find them separate. I do not attach 

 much importance to this, but, so far as it goes, it favours the views 

 of those — such as Megnin, Claparede, Dujardin, and Haller — who 

 hold that an Hypopus is a stage in a life history, not a separate 

 creature. 



Description. 



The whole creature is chitinous, somewhat transparent, yellowish 

 brown, with an irregular white band down the centre, caused 

 by th€f excretory organs showing through ; flattish on the dorsal, 

 slightly convex on the ventral surface. It has the appearance of 

 being divided into four parts, viz. : first, the rostrum, which is small 

 and broader than long ; secondly, the fore part of the cephalothorax, 

 extending from the rostrum to the epimera of the first pair of legs ; 

 thirdly, the hinder part of the cephalothorax ; and, fourthly, the 

 abdomen. The cephalothorax extends much further backward on 

 the ventral than on the dorsal surface. The legs of the two front 

 pairs are near together, as are those of the third and fourth pairs, 

 but there is a wide interval between the second and third pairs. The 

 abdomen and hinder part of the cephalothorax seem to show traces 

 of segmentation, a fact which Claparede observed in Mycoptes mus- 

 culmus, a species which, as above stated, appears to me to be more 

 closely allied to the present one than any other which I am 

 acquainted with. 



Male. 



Length (without legs) about 



Greatest breadth „ 



Length of rostrum as usually carried, about 



Breadth „ „ „ 



Length of first pair of legs about . 



„ second „ „ . . 



„ third „ „ . . 



„ fourth „ „ . . 



Rostrum, as seen from above, slightly curved in front, coming to 

 a sharp point at each side. It is, however, carried bent down upon 



