376 ME. A. D. MICHAEL ON HTPOPI, 



named authorities, and finally comes to a totally new conclusion, 

 viz., that Sypopus is a ferocious predatory parasite, and that it 

 eats its way into the body of its victim, and then devours its 

 whole internal [)artg, only leaving the skin. He quotes the 

 example of Bhipiphorus paradoxus, to show that a creature may 

 be an external parasite at one period of its life, and an internal 

 one at another. 



Notwithstanding Megnin's exposition, some acarologists of 

 eminence continued to consider Hypopus as a separate adult 

 creature, and continued to frame new species and genera for 

 newly discovered hypopial forms. Profs. Gr. Canestrini and E. 

 F. Fanzago's Cliironemus^ — afterwards changed to Tarsonemusf, 

 because the former word had been already employed for a genus 

 of fishes — consists of Hypopi. Dr. P. Kramer's female Den- 

 droptus% appears to be the same thing. Canestrini and Panzago 

 also preserve Dufour's genus Tricliodactylus^. The Lahidophorws 

 ^«Z^(2? of Kramer also appears to be a hypopial form||. In the 

 last-named paper Kramer also described another very singular 

 parasite of the Mole, which he called PygmepTiorus spinosus, which 

 has an immensely developed monodactyle claw to the front leg, 

 and somewhat rudimentary mouth-organs ; he described the male 

 only. B,. Canestrini subsequently added a new species, mesem- 

 Irince^, to Kramer's genus PygmepTiorus. 



Gr. Haller, in 1880, published a paper** upon Acarina parasitic 

 upon Tnvertebrata, in which is a summary of existing writings on 

 the subject, and in which, although he does not record any special 

 observations of his own upon the point, he suggests that the 

 hypopial form is a "travelling-dress" for Tyroglyphus,io enable 

 it to endure the journey from one fungus, &c., to another, which 

 would sooner or later be rendered necessary by the drying or 

 destruction of the fungus. 



* " Nuovi acari Italiani," Atti Soc. Veneto-Trentina di Sci. Nat. vol. v. fasc. i. 



t " Nuovi acari Italiani," ser. 2, ibid, 



\ " Ueber Bendroptus," Archiv fiir Naturg. xlii. Jahrg. (1876), p. 198. 



§ " Intorno agli acari Italiani," Atti E. 1st. Veneto di sci., lett. ed arti, ser. 5, 



vol. iv. p. 137. 



II "Zwei parasitische Milben des Maulwurfs," Archiv fiir Naturg. xliii. 

 Jabrg, (1877), p. 248. 



^ " Ooutribuzione alio studio degli acari parasiti degli insetti," Atti Soc. 

 Ven.-Trent. di Sci. Nat. vol. vii. fasc. ii. (1881). 



** 'Die Milben als Parasiten der Wirbellosen :' Halle, 1880. 



