154 BRITISH TYROGLYPHIDJ1. 



proximal in a telescopic manner ; they are thus 

 securely sheltered in the bag formed by the fold of the 

 membrane between the two segments. 



Andrew Murray,* in November, 1876, wrote at some 

 length on the subject of what a Hypopm was ; he does 

 not appear to have made any personal observations, 

 but he discusses almost all the above-named literature 

 respecting it. Finally he came to the conclusion that 

 Hypopus was a parasite, internal in the earlier part of 

 its life -history, external in the latter part ; and he 

 quoted the instance of Rhipiphorm paradoxns to show 

 that such a thing might exist. Presumably Murray 

 considered that the Hypopus ate its way into the body 

 of the host, and entirely devoured it, leaving only the 

 skin, but this is not very clear in his statement. 



Notwithstan ding Megnin's researches, Dr. P. Kramer, 

 in 1877,t described a homopial Hypopus found on the 

 mole as an adult creature under the name of Labido- 

 phorus talpse. This creature I have subsequently found 

 and bred, and find it to be the hypopial nymph of 

 GlycyphaguH Crameri. This is now universally admitted 

 to be correct ; it was admitted as such by Kramer in 

 c Das Thierreich.' In the same paper Kramer described 

 another parasite of the mole, and called it Pygmepli-orus 

 spinosus. In 1881 Berlese published a paper { in the 

 main agreeing with Megnin, stating, apparently cor- 

 rectly, that Hypopus does not take any nourishment ; 

 also that it was entirely devoid of buccal and anal open- 

 ings, which is not quite accurate, and that its lip with the 

 two hairs is a tactile organ, which is probable, but it 

 ordinarily serves also to cover up the mouth-opening. 

 Berlese also said that Kramer's Pygmephorus was a 

 Hypopus. This was an error. 



Gr. Haller, in 1880, published a pamphlet upon Acari 



* " Economic Entomology, Aptera," London, 1877, ' South Ken- 

 sington Museum Handbooks,' pp. 231 251. 



f " Zwei parasitische Milben des Maulwurfs," in ' Arch. Naturg.,' 

 xliii Jahrg., p. 248. 



J " Indagine sulle Metamorfosi di alcnni acari insetticoli," in ' Atti 

 1st. Yeneto,' ser. 5, vol. viii. 



