SHORT-TAILED GROUP 



3223 



with rounded foreheads. It includes most of the commoner species, such as the 

 edible crab {Cancer pagurus}, and shore crab (Carcinus mcenas). The former 

 belongs to the family Cancridce, characterized by having the carapace much wider 

 than long. As an article of food the male is more esteemed than the female, being 

 larger and having larger claws. The two sexes, as in all crabs, may be distin- 

 guished by the size of the tails, this organ in the male being narrower, more pointed, 

 and having fewer and smaller appendages than in the female. The family Can- 

 cridce is represented in tropical 

 seas by a large number of 

 species and genera, some of 

 which, such as Actcea, have 

 the carapace covered with 

 granules, and ornamented with 

 a network of deep grooves. 



The members of the 

 family Portunidce may be 

 recognized by a modification 

 of the last pair of legs. In the 

 great majority of crabs these 

 legs are like the rest, ending 

 with a long, slender-pointed YOUNG EDIBLE CRAB. 



foot, which bears evidence to 



its being an organ for running, climbing, or crawling; but in the Portunidce these 

 legs are much flattened, the last segment in particular being dilated into an oval 

 plate. The creatures are thus equipped with a pair of oars, by means of which they 

 swim. Several species of the typical genus Portunus are found in British waters, and 



many of them are hand- 

 somely colored, although 

 none are such expert 

 swimmers as the tropical 

 species, especially those 

 inhabiting- the gulf weed 

 of the Atlantic. The 

 peculiar motion of the 

 oar-like feet has given 

 rise to the name of 

 fiddler crabs, so often 

 applied to the group. 

 The figured species 

 ( Thalamita natator) is a 

 native of the tropical 

 seas. The common Brit- 

 ish shore or green crab 



{Carcinus mcenas~), which is referred to this family, differs from the rest in having 

 the legs of the last pair adapted for walking, being armed with a claw, and not 



SWIMMING CRAB. 



(Natural size.) 



