Trombidijormes 251 



Genera proposed for larvae whose subfamilial relationships are 

 unknown. 



I A St I g ma ^vuy?ini, 1911 



Type. Astigma oudemansi Bruyant, 1911 



2. Atomus Latreille, 1795 



Type. Acarus parasiticus DeGeer, 1778 



3. Cercothrombium Methlagl, 1928 



Type. Cercothrombium loricatum Methlagl, 1928 



4. Ettmiilleria OudQm2iX\s, 1911 



Type. 1 rombidium sucidum Tragardh, 1910 



5. Heterotrombidium Verdun, 1910 



Type. Thrombidium granulatum Oudemans, 1902 



6. Hexathrombium Cooreman, 1944 



Type. Hexathrombium spatuhferum Cooreman, 1944 



7. Hoplothrombium Ewing, 1925 



Type. Hoplothrombium quinquescutatum Ewing, 1925 



8. Monunguis Wharton, 1938 



Type. Monunguis streblida Wharton, 1938 



9. Neothrombium Oudemans, 1909 



Type. Allotrombidium neglectum Bruyant, 1909 (Allotrombidmm is 

 a lapsus for AUothrombium) 



10. Nothotromhicula Dumbleton, 1947 



Type. Nothotromhicula deinacridae Dumbleton, 1947 



11. Paratrombium Bruyant, 1910 



Type. Paratrombium egregium Bruyant, 1910 



12. PoM/^cfl Methlagl, 1928 



Type. Polydisca squamata Methlagl, 1928 



13. Womersleyia Radford, 1946 



Type. Womersleyia minuta Radford, 1946 



Discussion: The trombidiids are extremely numerous in both num- 

 bers and kinds. Thor and Willmann include 304 species in their section 

 on the family in "Das Tierreich." That this is only a fraction of the 

 species that await description is proved by the fact that almost every 

 collection of mites from litter will contain new species of trombidiids. 

 The next family, the Trombiculidae, has been studied more extensively 

 than the Trombidiidae. Thor and Willmann included these forms in 

 their account of the Trombidiidae as the subfamily Trombiculinae. 

 They listed 150 species of trombiculid, in addition to their 304 species 

 ot trombidiids. Even with 150 species they failed to include all the 

 new species discovered during World War 11. The total number of 

 trombiculids is now about 300, and many parts of the world have not 



