The structure of the cleaning brush on the pedipalps of some African Amblypygi (Arachnida)

The external structure of the cleaning organ or brush situated on the tarsus of the pedipalp in the Amblypygi has been examined in the following six species from tropical and southern Africa: Damon variegatus (Perty) Damon medius (Herbst), Titanodamon johnstoni Pocock, Phrynichus scullyi Purcell, Phrynichus bacillifer (Gerst.) and Hemiphrynus machadoi Fage.
In all except one of these species the organ consists of two approximately parallel rows of modified setae; in Hemiphrynus machadoi there is only one. When both rows are present the constituent setae of each are quite different in appearance and structure.
It is probable that the variations in number, size and shape of the setae in these forms furnish specific characters; further indirect support for this is afforded by the marked difference in the structure of the organ in Hemiphrynus as compared with the other five species; taxonomically Hemiphrynus belongs to the subfamily Tarantulinae while all the others are accommodated in the Phrynicinae or Damoninae.
A brush-like cleaning organ of some kind is found on the pedipalp-tarsus of both old and new world Amblypygi and most probably in all members of the order.