28 



Marvels of Pond-Life. 



called incus, the Latin for that implement. Each 

 hammer consists of two portions articulated by a hinge 

 joint. The lower portion, the manubrium, or handle, 

 gives motion to the upper portion, which from its 

 shape is named the uncus, or hook. The unci are 

 furnished with finger-like processes of teeth, which 

 vary in number. There are five or six in the best 

 developed specimens. These hooks or teeth work 

 against each other, and against the incus, or anvil, 

 which consists of distinct articulated portions, of which 



Gizzard of Notomata. 



the principal are two rami, or branches, jointed so that 

 they can open and close like a pair of shears. These 

 two rest upon the third portion, which is called the 

 fulcrum. Some faint idea of the working of the 

 toothed hammers may be obtained by rubbing the 

 knuckles of both hands together, but the motion is 

 more complicated, and the rami play their part in the 

 trituration of the food. Mr. Gosse states that when 

 an objectionable morsel has got as far as this mouth- 



