Mesostigmata 67 



5. Nemnichia Oudemans, 1936 



Type. Zercon eleganiulits Koch, 1839 (incomplete information, posi- 

 tion doubtful) 



6. Oocarpais Berlese, 1916 



Type. Oocarpais donisthorpei Berlese, 1916 



7. Parasitellus WiWmdinn, \9?>9 



Type. Eugamasus ferox Tragardh, 1910 



8. Pergamasus Berlese, 1903 



Type. A cams crassipes Linnaeus, 1758 



9. Trachygamasiis Berlese, 1906 



Type. Gamasus pusillus Berlese, 1892 



Discussion: Parasitid mites are found typically in accumulations of 

 organic material such as rotting logs and litter. They are of no known 

 economic or medical importance. However, since they are predaceous 

 they probably aid in the destruction of many small insects. 



References: 



Berlese, A. 1905. Monografia del genere Gamasus Latr. Redia 3:66-304 



+ 18 PI. 

 Oudemans, A. C. 1939. Neue Funde auf dem Gebeite der Systematik und 

 der Nomenklatur der Acari. IV. Zool. Anz. 126:195-201. 



Macrochelidae Vitzthum, 1930 



Figure 52 



Diagnosis: The elongated, usually clawless leg i of macrochelids will 

 distinguish them from other gamasids. The ventral plates of the fe- 

 males are also diagnostic. The sternal plate bears three setae and two 

 pores. The metasternal plates are minute and not fused with endopodal 

 plates. Each metapodal plate bears a seta and a pore at its anterior 

 border. The epigynial plate is truncate anteriorly and posteriorly; it 

 bears a single pair of setae. The ventral plate is fused with the anal 

 plate and may be considerably reduced. The tectum consists of a me- 

 dian, narrow, branched or toothed element that may or may not be 

 flanked by smaller lateral elements. The dorsal plate is usually entire. 



Genera and subgenera: 



1. Macrocheles Latreille, 1829 

 a. Machrocheles s. str. 



Type. Acariis muscae Scopoli, 1772 (= Acarus marginatus Her- 

 mann, 1804) 



