Sessiluncus G. Canestrini

Castilho, Raphael C., Silva, Edmilson S., De, Gilberto J. & Halliday, Bruce, 2016, Catalogue of the family Ologamasidae Ryke (Acari: Mesostigmata), Zootaxa 4197 (1), pp. 1-147: 22

publication ID 10.5281/zenodo.168445

publication LSID

persistent identifier

treatment provided by


scientific name

Sessiluncus G. Canestrini


Sessiluncus G. Canestrini  (15 described species)

Movable and fixed cheliceral digits with three and 2–5 teeth, respectively. Epistome with an anteromedian extension wider at base, flanked by a pair of large anterolateral extensions or spines, shorter than anteromedian extension. Seta h 3 about in longitudinal line with h 1 and posterior and mediad to h 2. Idiosoma suboval, 440–620 µm long and 260–400 µm wide at widest level. Podonotal and opisthonotal shields fused, forming holonotal shield. Dorsal idiosomal setae aciculate and smooth or slightly pilose. Podonotal region of dorsum with 19–21 pairs of setae, of which 19–21 pairs on podonotal shield and without setae on soft integument along lateral margins of podonotal shield. Opisthonotal region with 17–19 pairs of setae, of which 17–19 pairs on opisthonotal shield and without setae on soft integument along lateral margins of opisthonotal shield. Seta j 1 not on prominent protuberance, longer than, as long as or shorter than r 3 and Z 5. Holonotal and ventrianal shields separated. With a pair of presternal platelets (fused to sternal shield in S. heterotarsus  and S. reticulatus  ). Sternal shield fused to endopodal shield near coxa IV; setae st 1– st 4 in longitudinal line. Opisthogaster without platelets between genital and ventrianal shields; with 5–9 pairs of setae on ventrianal shield and 0–2 pairs on soft integument around ventrianal shield; post-anal seta longer than, as long as or shorter than para-anal seta. Peritreme with straight or smoothly curved margins, extending anteriorly to level between of middle region of coxa II and coxa I. Peritrematal shield not fused posteriorly to exopodal shield near coxa IV. Exopodal shields near coxae II –III –III divided at median level of coxa III. Without distinct metapodal platelets. All legs with pretarsi; pre-tarsus I sessile, its base broadly fused to tarsus. Genua I, III and IV and tibia IV with 13, 8, 9 and 9 setae, respectively.