Medical Definition of ARTHRODESIS. : the surgical immobilization of a joint so that the bones grow solidly together: artificial ankylosis. the surgical immobilization of a joint so that the bones grow solidly together. ADVERTISEMENT.
Trapdoor spiders are not particularly harmful to man however, like Tarantulas, the tiny hairs on the legs of some species leave tiny red marks where the toothed hairs on the spiders' feet have clung to the skin. Mouse spiders are also a type of Trapdoor spider with huge chelicerae and may measure up to 35mm in body length.
Rating Newest Oldest. Best Answer: There are only three spiders poisonous to humans in North America. The Brown recluse, the Black widow and the newly introduced Brown widow. From wikipedia: The grass spiders are members of the genus Agelenopsis.They weave sheet webs that have a funnel shelter on one edge. The web is not sticky, but these spiders make up for that shortcoming by running very rapidly. They may be recognized by the arrangement of their eight eyes into three rows.rom wikipedia: The grass spiders are members of the genus Agelenopsis. They weave sheet webs that have a funnel shelter on one edge. The web is not sticky, but these spiders make up for that shortcoming by running very rapidly. They may be recognized by the arrangement of their eight eyes into three rows.