34 DANGEROUS MARINE ANIMALS 



Sea Blubber, Cyanea capillata Eschscholtz. (Fig. 13). In- 

 habits the North Atlantic and Pacific, southern coast of New Eng- 

 land to the Arctic Ocean; France to northern Russia, Baltic Sea; 

 Alaska to Puget Sound, Japan, and China. Other stinging species 

 of this genus are found in the tropical and temperate Pacific Ocean. 

 III. Anthozoa: The sea anemones and corals. Important veno- 

 mous members of this group are : 



Elk Horn Coral, Acropora palmata (Lamarck). (Fig. 14). 

 Inhabits Florida Keys, Bahamas, and West Indies. 



Sea Anemone, Actinia equina Linnaeus (Frontis). Inhabits 

 the eastern Atlantic from the Arctic Ocean to the Gulf of Guinea, 

 Mediterranean Sea, Black Sea, and the Sea of Azov. 



Rosy Anemone, Sagartia elegans (Dalyell) (Frontis). In- 

 habits Iceland to Atlantic coast of France, Mediterranean Sea, and 

 the coast of Africa. 



Sea Anemone, Adamsia palliata (Bohadsch) (Frontis). Ranges 

 from Norway to Spain, and the Mediterranean Sea. 



Sea Anemone, Anemonia sulcata (Pennant) (Frontis). East- 

 ern Atlantic, from Norway and Scotland to the Canaries, and the 

 Mediterranean Sea. 



Venom Apparatus of Coelenterates. The venom apparatus of 

 coelenterates consists of the nematocysts or stinging cells 

 which are largely located on their tentacles (Fig. 15). These 

 nematocysts are situated within the outer layer of tissue of the 

 tentacle. Each of the capsule-like nematocysts is contained within 

 an outer capsule-like device called the cnidoblast. Projecting at 

 one point on the outer surface of the cnidoblast is the trigger-like 

 cnidocil. Contained within the fluid-filled capsular nematocyst is 

 the hollow, coiled, thread tube. The opening through which the 

 thread tube is everted is closed prior to discharge by a lid-like device 

 called the operculum. The fluid within the capsule is the venom. 

 Stimulation of the cnidocil appears to produce a change in the 

 capsular wall of the nematocyst causing the operculum to spring 

 open like a trap door, and the thread tube conveying the venom is 

 everted. The sharp tip of the thread tube penetrates the skin of the 

 victim and the venom is thereby injected. When a diver comes in 

 contact with the tentacles of a coelenterate, he brushes up against 

 the cnidocils of literally thousands of these minute stinging organs. 



Medical Aspects. The symptoms produced by coelenterate stings 

 vary according to the species, the site of the sting, and the person. 

 In general, those caused by hydroids and hydroid corals (Mille- 



