A SYNOPSIS OK AL'STKAT.IAN ACAKIXA — RAINBOW. 175 



Family UKOPODIDJi. 

 The Uropodidie are distinct from the two preceding famiUes in 

 general appearance. The mites are small. They are usually 

 found attached to insects, and are remarkable for the length of 

 their mandibles, which are often twice as long as the body, 

 slender, and terminating in delicate chelfe. They are not, strictly 

 speaking, parasitic, their presence upon insects being for the 

 purpose of transportation ; moreover, those found upon insects, 

 are attached by a pedicel of excrement, and owing to the fact 

 that they are immature, have been termed nympha pfdiinculata. 

 Up to the present two species have been described from Australia. 



Gpiuis Uropoda, Lafv. 



UrOPODA SPINULIPES, Cdtif'sf. 



Uropnda spmul'i])f'i<, Canest., Atti. 1st. Venet., (C), ii., li^So, p. 

 7U. 



Hah. — Australia (on a Geotrupid). 



GenvH Fedrizzia, Caufxf. 



Fedrizzia grossipes, Canest. 



Fedrizzia yrosi^ijjes, Canest., Atti. 1st. Venet., (G), ii., l^So, p. 

 707, pi. viii., f. 1 and 2. 



/lab. — Australia (on a Geotrupid). 



Super-familn ORIBATOIDEA. 



The Acarids included in this group are popularly known as 

 " Beetle Mites." They ai'e small and hard ; some have rather 

 short legs, and others extremely long ambulatory limbs. Super- 

 ficially, these mites have a very beetle-like appearance, and this is 

 doubtless the origin of the popular name. Oribatids may be 

 easily distinguislied from all other Acarids by the presence of a 

 hair or seta which is seated on either side of the cephalothorax, 

 and this arises from a small \xnv. Tliese are usually termed 

 jjseudu-stiyniaUe, and their function is unknown. The super- 

 family under consideration is an extensive one and widely 

 distributed. The species occur on dead wood, lichens, in moss, 

 amongst dead leaves and forest debris generally ; some are 

 aquatic, occurring in mangrove swamps and on fresli-water and 

 marine Algie ; a few species are amphibious. These Acarids 



