-pycnogonida-

‖n. pl. [ NL., fr. Gr. &unr_; thick crowded + &unr_; knee. ] (Zool.) A class of marine arthropods in which the body is small and thin, and the eight legs usually very long; -- called also Pantopoda. [ 1913 Webster ]

☞ The abdomen is rudimentary, and the triangular mouth is at the end of a tubular proboscis. Many of them live at great depths in the sea, and the largest of them measure two feet across the extended legs. [ 1913 Webster ]