MUSSELS. 



75 



Figure 29. 



shown in Figure 28. The shell is thin and delicate, 

 and you notice that the umbo, or shoulder, is not 

 quite at one end, as in the true mussel. 

 Figure 29 shows the shape of another 

 small mussel, which sometimes lives un- 

 der stones. Its shell is full of wrinkles. 

 But the oddest of the whole family of 

 mussels is the Pea-pod Shell, shown in 

 Figure 30. This mussel is not content 

 with fastening itself by threads, but it also bores 

 a deep hole into the very rock, creeping inside as 

 it grows, and leaving only a little opening for the 

 water to come and go. 



As the shell grows larger, the creature bores 

 deeper, and thus it passes its life safely, though 



how little 

 it knows 

 of what is 



Figure 'M. 



in the great world! 

 are not a mussel? 



going on 

 Are you not thankful that you 



BliACKBOARD WORDS. 



byssus (bis'-sus). A group of threads which hold a shell to a 



rock. 

 securest (se-kur'est). In the safest and surest manner, 

 delicious (de-lish'us). Having a fine flavor. 

 harpoon (har-pobn'). A spear to which a cord is attached. 



It is used for catching whales and seals. 



