MARINE ANIMALS THAT STING 



41 



PROBOSCIS 

 TENTACLES FO 



SIPHON 



VENOM DUCT 



RADULAR SHEATH 



VENOM 

 BULB 



PROBOSCIS 



ESOPHAGUS 



Fig. 17. Top: The external anatomy of a cone shell. (Kreuzinger) Bottom: 

 Anatomy of the venom apparatus of Conns. (Hon) 



Stinging or Venom Apparatus of Cone Shells. The venom ap- 

 paratus consists of the venom bulb, venom duct, radular sheath, 

 and radular teeth (Fig. 17) . The pharynx and proboscis, which are 

 a part of the digestive system, also play an important role as acces- 

 sory organs. The venom apparatus lies in a cavity within the ani- 

 mal. It is believed that preparatory to stinging, the radular teeth 

 which are housed in the radular sheath are released into the 

 pharynx, and thence to the proboscis, where they are grasped for 

 thrusting into the flesh of the victim. The venom, which is believed 



