72 INVERTEBRATE ANIMALS. _ 



toothed ou the margin, and probably serving for shovels 

 in excavating holes in the sea-bottom, in which the 

 animals take shelter whilst watching for their prey. 



The Plated-lobsters, Galatheidcs, resemble the pre- 

 ceding in habit. Mr. Couch observes, with reference to 

 Galathea strigosa, "It is very remarkable to witness the 

 accuracy with which they will dart backward for several 

 feet into a hole very little larger than themselves ; this 

 I have often seen them do, and alvways with precision." 

 The arrangement of M. Edwards is followed in the 

 retention of Galatheidce in the tribe Macroura. 



II Examples of Scyllarus, Ihamis, and Galathea ; 

 and of Mglea lavis, a fresh-water species from Chili, 

 collected and presented by Capt. J. A. Perry. 



Tribe ANOMOUKA. avoixog, irregular ; ovpu, a tail. 

 The Crustacea of this tribe exhibit an advance in 

 organisation, the anterior or cephalo-thoracic portion of 

 the body being more developed in comparison with the 

 abdominal portion than in the Macroura. 



Group 173.— Section ANOMOURA INFERIORA (Dana) in 

 part. 



Sub-tribe PAGURIDEA. Hermit-crabs. 



In the Soldier-crabs, or Hermit-crabs, the abdomen 

 is long, weak, and tender ; it is always inserted into 

 the cavity of some cast-off marine shell, of which the 

 crab becomes the tenant, changing, however, its habita- 

 tion for a more commodious one as it increases in size. 

 Shells occupied by P. PrideauxU, a British species, 

 very frequently afford a resting-place for the Sea Ane- 

 mone, Adamsia maculata. When the Crab changes its 



