CHEESE MITES, ETC. 263 



CASE transformations, or supposed transformations, of Hypopus. It is 



T 1 • 



a long smooth species with a projecting sow-like snout. In 

 accordance with his opinion that Hypopus is only a stage of 

 Tyroglyphus, he gives as a synonym of it the Acarus spinitarsus 

 of Hermann, which is undoubtedly a Hypopus. 



xa. 13- 



Figure of Tyroglyphus mycophagus. Capied from Megnin's figure. 



Nos. Sub-Genus Tyroglyphus (Lafr.) 



Feeds on animal products. Tarsi, with suckers and claw. 



Tyroglyphus entomophagus {Laboulb., Ann. Soc. Ent. Fr. 1862.) — 12. 

 Sketch of a particle of dust from an insect drawer much magnified, 

 showing the mite in various stages, eggs, broken fragments, &c. ; 13. 

 Magnified sketch of insect. 



The Tyroglyphus entomophagus is the smallest of all the 

 known species of this genus. It is remarkable for the parallelism 

 of the sides, and cylindrical appearance of the body, and for its 

 narrowness, especially in the female. Its legs are shorter than in 

 the other species. 



It is a species only too well known to Entomologists. It takes 

 up its abode in entomological collections, in the interior of the 

 body or on the surface of the insects, and in the dust which 

 gathers at the bottom of the drawers or boxes. Large insects, 

 with the body full of fatty particles, those which have not lived 

 long or which have been brought up in captivity, and which have 

 not paired, and those which have become greasy, (to use the tech- 

 nical expression), are the most hable to attack. Certain families 

 of Coleoptera, the large Scarabaeid^, like Oryctes and Geotrupes, 

 the Lucanidae, the Carabidae, the Dytiscidae, and the Hydro- 

 philidae, the Cerambycidse, the large or badly dried Blaptidae, may 

 often be seen covered on the surface with excrement and eggs, 



