(Subclass Copepoda):
A paired, ventral sclerite modified to form a spinoform, tapering process located on the ventral surface of the cephalothorax in some siphonostomatoids (e.g. Caligidae) and poecilostome cyclopoids (e.g. Taeniachanthide) [Boxshall and Halsey, 2004].
Crustacea glossary. Natural History Museum of Los Angeles County. 2011.