248 STALK-EYED CRUSTACEA 



very high and distinct. The inferior branchial regions 

 are naked, but roughened with numerous short, sharp 

 rugae. 



The first pair of legs is of unequal size in both sexes. 

 In the large limb the fourth joint is triquetal, very stout, 

 and reaches slightly beyond the margin of the carapace ; 

 the anterior surface is flat, and both its margins are 

 armed with very large and prominent tubercles directed 

 forwards ; on the outer surface and the posterior angle, 

 which is obtuse, there are short granulous rugcT, which 

 are very conspicuous on the angle. The larger hand is 

 very large and stout ; the fingers are very stout, with 

 the outer edges armed with small, horny tubercles ; the 

 prehensile edges gape but slightly, and are armed with 

 large, irregular teeth. The walking legs are stout, with 

 the fifth and sixth joints and the lower anterior angle of 

 the fourth clothed with long black hairs. 



In the male the abdomen is broadest at the third 

 segment, then triangular ; in the female, at the fifth 

 and sixth joint. The first pair of male abdominal 

 appendages has a long, slender horny tip curved in a 

 spiral. 



Range. — West Coast of America, Lower California, 

 Chili. 



4. Uca. 



Uca .... Leach, H. Milne Edwards, 



Cancer . . . Herbst. 



Gecarcinus . . Latreille, Desmarest. 



The carapace is wider than long, oval, and very 

 elevated ; very curved from before backwards. The 

 front is narrower than in the other Gcocat'cinidcB] very 

 sloped and almost semicircular. The orbits are very 



