398 GASTEROPODA. 



by the tegumentary glands, there is in the interior of the animal a 

 special apparatus apparently destined to furnish a viscid fluid of 

 a similar character. The gland alluded to, called by Cuvier,* 

 par excellence, " the secerning organ of the viscosity," is in the 

 snail a triangular viscus (Jig. 183, ) placed in immediate con- 

 tiguity with the pericardium. On opening it, it is found to be 

 filled with an infinite number of very thin laminae that adhere to 

 the walls of its cavity by one of their edges, and become joined to 



Fig. 183. 



each other as if by communicating branches. The excretory duct 

 of this slime-secretor, which, we may observe, is found to exist in 

 many other genera of Gasteropods, accompanies the rectum to its 



* Histoire des Mollusques ; M6moire sur la Limace et le Colima^on. 



