(Subclass Branchiura):
On underside of cephalothorax, unpaired projection anterior to proboscis. Distal half of anteriorly directed preoral sting can be retracted into basal socket. Needlelike tip nears opening of poison gland. Used to puncture host. (Syn. preoral spine) [Stachowitsch, 1992].
(Subclass Branchiura):
Retractile piercing mechanism with poison gland [McLaughlin, 1980].
Crustacea glossary. Natural History Museum of Los Angeles County. 2011.