MASKS AND FACES 53 



lateral margins of tlie carapace and the buccal frame. 

 Milne-Edwards remarks that the grooves are often em- 

 phasised about the middle of the carapace, so as to pro- 

 duce the appearance of the capital letter H, the transverse 



Fig. 2.—Ethusa mascarone (Herbst), IHerbsf] 



line being the upper boundary of the cardiac region. In 

 some cases the grooves are so arranged as to represent 

 very strikingly a human countenance or the caricature of 

 one, as in the Masked Crab of Great Britain and the grimac- 

 ing Ethusa mascarone of the Mediterranean, which is here 

 shown as depicted by Herbst. Such likenesses the old 

 writers were not at all disinclined to accentuate. 



The Brachyura are divided into tribes, in regard to 

 which, however, there is not at present any absolute agree- 

 ment among naturalists. We shall here arrange them 

 under the names Cyclometopa, Catometopa, Oxyrrhyncha, 

 Oxystomata, Anomala. It is melancholy, but scarcely 

 avoidable, that an alternative list of names should have to 

 be mentioned, for these tribes in the same succession may 

 be called — Cancroidea, Ocypodiidea, Maioidea, Leucosiidea, 

 and Anomura apterura. The subjoined table will be use- 

 ful for reference. 



