HYPOPID^, 233 



CASE ratus, he called Anoetus, from the Greek word meaning incom- 

 prehensible. He found a number of individuals upon the under- 

 wing of a bee. All that he saw of its organisation, its haunches 

 drawn near each other, and contiguous to the median line, and 

 occupying more than two-thirds of the whole length, the head 

 rudimentary or null, and replaced by a short blade, with two 

 bristles in front, but without any trace of mouth, its feet quite 

 unfit for walking, and the four posterior ones almost rudimentary; 

 finally, the ten or twelve sucker-cups on the underside of the 

 abdomen, behind the haunches, prevented his suspecting the 

 slightest analogy with that which has been so imperfectly 

 described, and figured under the name of Hypopus. 



M. Gervais, in 1844, in the Apteres ("Suites a Buffon"), looked 

 upon Hypopus as a sub-genus of Tyroglyphus, and characterised 

 it by the ellipsoid, flat, coriaceous body, the absence of palpi, by 

 an oblong lip, short feet, without claws, terminated by vesicular 

 caruncle. But M. Dujardin says; this last character is opposed to 

 what Duges saw of the feet of his Hypopus spinitarsus, neither 

 does the flattened form agree with the former species, as Her- 

 mann had already described. 



Koch, in his great work on the Arachnids of Germany 

 (" Deutschland's Crustaceen "), had taken no account of the 

 genus Hypopus; but later, in 1843, in his " Ubersicht," he 

 takes up the genus, and places in it two other species, which he 

 "had formerly included under Uropoda. 



That was the state of affairs when M. Dujardin, who had made 

 a profound study of the subject, satisfied himself that his Anoetus 

 was only a Hypopus. He found, like De Geer, the Acarus 

 muscarum on flies, and in such abundance on the abdomen and 

 thorax, that these parts seemed clothed as if with a granular 

 tissue. All these Hypopi hold themselves there immovable, 

 fixed indifferently on different parts of the skin of the animal by 

 the suckers on the after-part of the abdomen, which seem to have 

 no purpose but to fix them solidly, and being placed posteriorly 



