Opisthosoma

Portion of the body posterior to the legs in a tick or mite.

opisthosoma

the abdomen of the scorpion, consisting of seven mesosomal and five metasomal segments. The opisthosoma also bears the genital pore and opercula (1st segment), the pectines (2nd segment), and four pairs of book lung openings on the sternites.
Found on http://www.vaejovidae.com/Glossary.htm
No exact match found