radioles

Noun

radiole (plural radioles)

1. The spine of a sea urchin.
   • Radioles or spines [...] are the appendages articulating upon the tubercles. The different parts of the spines are the socket by which it is articulated to the tubercles; the lower part of the radiole is called the head, and is separated from the neck, which is usually smooth or finely striated, by...1874, Alexander Agassiz, “Terminology”, in Revision of the Echini (Illustrated Catalogue of the Museum of Comparative Zoölogy, at Harvard College; VII), part IV (Structure and Embryology of the...
2. A heavily ciliated feather-like tentacle occurring in clusters on the crowns of certain tubeworms, especially those of the order Canalipalpata (fan-head worms), used for feeding and respiration.
   • Fabricia bikinii, n. sp. [...] The tentacular crown is composed of three pairs of symmetrical radioles; in addition there are shorter, entire, paired filamentous processes, or palpi, at the ventral end of the crown [...]. Each radiole has 6 to 8 pairs of slender filaments that arise along the basal...1954, Olga Hartman, “Systematic Descriptions”, in Marine Annelids from the Northern Marshall Islands: Bikini and nearby Atolls, Marshall Islands (Geological Survey Professional Paper; 260-Q)...