In recent times the term tarantula has been applied indiscriminately to many different kinds of large spiders in no way related to Lycosa tarantula; and to at least one Arachnid belonging to a distinct order.
The bi-ramose structure of the post-oral limbs, demonstrated by Beecher in the trilobite Triarthrus, is no more inconsistent with its claim to be a primitive Arachnid than is the foliaceous modification of the limbs in Phyllopods inconsistent with their relationship to the Arthrostracous Crustaceans such as Gammarus and Oniscus.
In Queensland one of the largest local spiders, known as Holconia immanis, a member of the family Clubionidae, bears the name tarantula; and in Egypt it was a common practice of the British soldiers to put together scorpions and tarantulas, the latter in this instance being specimens of the large and formidable desert-haunting Arachnid, Galeodes lucasii, a member of the order Solifugae.
Arachnidism-Poisoning resulting from the bite or sting of an arachnid.
Accordingly the diplostichous ommatoeum or soft tissue of the Arachnid's central eye should strictly be called " triplostichous," since the deep layer is itself doubled or folded.