GLOSSARY. 305 
Wuort. The spiral turn of a univalve shell. 
XrpHosuRA (Gr. xiphos, a sword; and oura, tail). An order of Crustacea, 
comprising the Limuli or King-Crabs, characterised by their long sword- 
like tails. 
XYLOBIUS (Gr. zulon, wood; dios, life). An extinct genus of Myriapods, 
named in allusion to the fact that the animal lived on decaying wood. 
ZAPHRENTIS (proper name). A genus of Rugose Corals. 
ZEUGLODONTIDE (Gr. zeuglé, a yoke ; odous, a tooth). An extinct family of 
Cetaceans, in which the molar teeth are two-fanged, and look as if composed 
of two parts united by a neck. 
ZOOPHYTE (Gr. zodn, animal ; phuton, plant). Loosely applied to many plant- 
like animals, such as Sponges, Corals, Sea-anemones, Sea-mats, Xe. 
