NA TURAL SCA VENGERS. 1 5 1 



devouring decaying vegetation. The common peri- 

 winkle (Littorina littored) is another good scavenger, 



Fig. ill. 



Ormer (Haliotis titberculata). 

 Fig. 112. 



Limpet (Patella vulgaris). 



but a voracious feeder. The limpet (Patella md- 

 garis) does its work more slowly, but effectively, and 



