INVERTEBRATE ANIMALS. 71 



Group 174.— ANOMOURA SUB-MEDIA. Dana. 

 Sub-tribe LTTHODEA. Stone-crabs. 

 Not more than about six species are known belonging to 

 this group. 



II The Northern Stone-crab, Lithodes Maia, is 

 found occasionally on the coasts of Scotland 

 and the Isle of Man. The colour whilst the 

 animal is living is yellowish red ; that of an 

 alhed species from Fuegia is cherry-red. The 

 Porcupine Stone-crab, Lithodes hystrix, is from 

 Japan. The Noduled Stone-crab, Echinocerus 

 ciharius, is from the Columbia Eiver. It is 

 probable that all the species are weak slow- 

 moving animals, and that their strange aspect 

 corresponds in some way with their more than 

 ordinary need of protection. 



Group 175.— ANOMOURA MEDIA. Dana. 



Sub-tribe PORCELLANIDEA. Porcellain-crabs. 



The little Porcellain-crabs are the butterflies of the 

 class. Many species frequent coral reefs and as 

 described and figured by D'Orbigny and other writers 

 exhibit elaborate ornamentation and vivid colouring. 

 One species is wholly of a bright scarlet-lake, another 

 of a deep mazarin-blue, a third is rose-colour, with 

 bands of snow-white fringe crossing the carapace ; other 

 more sombre species, including the "Broad-claw" of 

 our own coasts, have series of long and delicate lashes, 

 serving as nets or strainers for the capture of animal- 

 cules. The Hippidea are small Crustaceans found chiefly 

 in the Pacific. 



Estimated number of species : recent, 34 ; British, 2. 

 IT Examples of Porcellana, Remipes, Alhunea, &c. 



