268 



THE SEA 8EOEE 



the weeds of the coast. A few of the latter are shown in the 

 accompanying illustration, including the Sea Pill-ball (Nescea 

 bidentata), common on the rocky coasts of the south-west, and 

 distinguished by the two sharp projections on the last segment ; 

 the Serrated Pill-ball (Sphceroma serratum), very common on 

 most rocky shores, and characterised by the fine sawlike teeth on 

 the outer edge of the outer plates of the ' tail ' ; the Great Sea- 

 slater (Ligia oceanica), also an abundant species ; the Spotted 

 Hog Louse (Oniscoda maculosa) that lives among the tufted sea 

 weeds ; and the Boring Pill-ball (Limnoria lignorum) that bores 



5 



FIG. 200. MARINE AMPHIPODS 



1. The spined sea screw (Dexamine tpinosa). 2. Westwoodia ccecvla. 8. Tetromatus 

 typieus. 4. The sandhopper (Orchestia littorea). 5. Montagua monoculotdes. 

 6. Iphimedia obesa. All enlarged 



into the woodwork of piers and jetties, often doing considerable 

 damage. 



The above and other isopods feed on various animal and 

 vegetable substances, some species being quite omnivorous in 

 habit. Most of them are eagerly devoured by birds and fishes. 



The Amphipods, six species of which are shown in the above 

 illustration, include the Sandhoppers or Beach Fleas, so numerous 

 on our coasts that it is almost impossible to go any distance 

 without making their acquaintance. They are invaluable as 

 scavengers, as they rapidly devour decaying sea weeds, and will 

 speedily reduce the body of any animal washed on the beach to 



