Variations: Rhax, Rhagion, Rhogalida (“grape-spider”)
The name Rhox indicates similarity to a grape. It may be the same as the spider known as rhogalida or “grape-spider” on Crete, although nobody is quite sure what a rhogalida is either. Aelian places it in Libya, but it is otherwise described as a common Mediterranean spider.
In any case the rhox, as described by Nicander, Philumenus, and Pliny, is a sort of spider or phalangion. has a toothed mouth in the middle of its stomach and short, stubby legs that move in succession – a description more reminiscent of a millipede or centipede than a spider. It is smoky or pitchy black in color. Its venom is instantaneously deadly, and known symptoms include web-like strands in the urine.
The short legs may be a misinterpretation, as the description and lethality both suggest the malmignatte or Mediterranean black widow.
References
Beavis, I. C. (1988) Insects and other Invertebrates in Classical Antiquity. Alden Press, Osney Mead, Oxford.
Kitchell, K. F. (2014) Animals in the Ancient World from A to Z. Routledge, Milton Park, Abingdon, Oxon.