214 



VENOMOUS ANIMALS 



poison, and possesses three or four strong conical teeth curved with 

 an anterior convexity. These teeth are not grooved or channelled, 

 but are easily moved and erected, and are enclosed in a sheath 

 formed by the mucosa of the palate. The poison collects between 

 the teeth, and simply flows down them into the wound. 



The venom has not been studied, except so far as to show that it 

 has some digestive action. The effect on man is not certainly 

 known, but is supposed to lead to syncope. 



Another fish, the bite of which is much dreaded, is Tetrodon 

 fiuviatilis, which is found in the waters of Indo-China, and fre- 

 quently attacks the natives, especially children. 



CLASS II. 



Fish which Poison by Means of Stings associated with 

 Poison Glands. 



Bottard classifies the poison apparatus of this class into three 

 groups : — 



1. Apparatus entirely closed, and therefore before the poison can escape 



a membrane must be ruptured : — 



Synanceia brachio. 



,, verrucosa. 

 Plotosus anguillaris. 



2. Apparatus partially closed: — 



Thalassophryne reticulata. 



maculosa. 



3. Apparatus in more or less direct communication with the exterior: — 



Trachinu s ^vipera . 



draco, 

 radiatus. 



' araneus. 

 Cottus scorpius. 

 ,, bubalis. ; fin 

 gobio. 

 Callionymus lyra. 

 Scorpaena porcus. 



scrofa. 

 Pterois antennata. 

 Pelor filamentosum. 

 Acanthurus luridus. 

 Uranoscopus scaber. 

 Trigla hirundo. 



The poison glands are generally placed at the base of the dorsal 

 or anal fins, or under spines on the operculum. The gland com- 

 municates with one or more rays of the fins. The barbs may be : — • 



1. Grooved, but having the groove converted into a canal by a 

 membrane, which must be ruptured for the poison to escape. 



2. Canalized by channels which lead to apertures near its tip. 

 This arrangement of the rays agrees with the types of poison 



apparatus mentioned above. 



