Mesostigmata 99 



Genera: 



\. Thinozercon Halbert, 1915 



Type. Thinozercon michaeli KsilbeTt, 1915 

 2. Dithinozercon Berlese, 1916 



Type. Thinozercon {Dithinozercon) halberti Ber\ese, 1916 



Discussion: This family is very poorly known. Both included genera 

 are monotypic. Thinozercon is from the Old World, and Dithinozercon 

 from the New. Probably many new forms in this group await dis- 

 covery. 



References: 



Berlese, A. 1916. Centuria terza di acari nuovi Redia 12:295. 

 Halbert, J. N. 1915. Clare Island Survey, part 39:11. Proc. Roy. Irish 

 Acad. 31:82. 



Dasyponyssidae Fonseca, 1940 



Figures 70-73 



Diagnosis: Both sexes have a divided dorsal plate. The peritreme of 

 the female extends dorsally and transversely between the anterior and 

 posterior sections of the dorsal plates, while that of male flanks the 

 anterior dorsal plate for a short distance. Leg i of both sexes is re- 

 markably enlarged so that it is more than twice as stout as legs ii-iv. 

 Body setae show some sexual dimorphism, those of the female being 

 expanded, while those of the male are normal. Ventral plates of the 

 male are divided. Sternal plates i and ii are fused to a single plate in 

 which the male genital opening is situated. Sternal plates iii and iv 

 are fused on each side but are separated at the midline. The ventral 

 plate is reduced and has a single pair of setae. The anal plate has seven 

 pairs of setae and one median posterior seta. 



Genus: 



Dasyponyssus Fonseca, 1940 



Type. Dasyponyssus neivai Fonseca, 1940 



Discussion: Dasyponyssus neivai was discovered in Brazil on an ar- 

 madillo. It is here placed in the Thinozerconina because of its obvious 

 morphological affinities with Thinozercon. It does, however, show 

 some relationship to the Gamasides and may even represent a distinct 



