Arachnula is a genus of amoeboid protist first described by Leon Cienkowski in 1876.It's phylogenetic position is a subject of some controversy. David Bass and colleagues considered it to be a vampyrellid within the Endomyxa clade of Rhizaria, and the SSU rDNA sequence isolated from an organism described as Arachnula impatiens is indeed very close to that of the vampyrellid Theratromyxa.