150 NATURAL HISTORY OF OUR SHORES 



to the lowest zone. The upper surface and all the limbs 

 are thickly covered with a velvetlike coating of hairs, long 

 and fringelike at the outer edge of the claws. It will be 

 noticed that the movable finger of the claws is so shaped 

 that when the crab draws its claws towards the body they 

 fit exactly to the front of the carapace, so that when legs 

 and all are closed in the crab is a circular disc about the 

 size of a penny. The hairs hold mud and ooze, and thus 

 covered it easily escapes detection, even when it leaves its 

 hiding-place and perches against the side of a rock. 



We have but two representatives of the genus, the other 

 is the little Porcellana longicornis, about as big as a split pea. 

 This one is not velvet coated, but smooth and bright. In 

 colour it varies much : red, brown, white, or green ; some- 

 times mottled with all these colours. It is still more 

 abundant than the last, and found in similar localities. 



An examination of the tail of these two last species will 

 show that it is still on the hermit type, only that the side 

 fins are reduced to microscopic dimensions, the porcelain 

 crabs having assumed the general form of the Brachyura. 



In these, as well as in the species which follows, the 

 vestigiary hind legs are not always visible outwardly, as 

 they have an adaptation for packing them under the hinder 

 edge of the carapace. 



Most striking of all the Anomoura is " the Great Stone 

 Crab " (Lithodes maia Fig. 61). At a casual glance the 

 non-naturalistic observer would easily mistake it for the 

 " Great Spider Crab " (Maia squinado). A full-grown male 

 measures about seven inches across the carapace, and has 

 a spread of limb about twenty inches. The colour is pink, 

 with a purple shade. 



On looking at the under side of a Lithodes, it will be 

 noticed that the abdomen is membraneous, except for some 

 triangular shelly plates (as in some foreign hermit crabs), 

 marking each segment, and that the segments do not follow 



