232 A HISTOKY OF EECENT CKUSTACEA 



except on the chelae, which are mottled with yellow.' 

 Krauss at Natal found Alpheus Edwardsii in monstrous 

 numbers in the mud of the bay, in which, he says, they 

 dig deep perpendicular holes. When the tide is out they 

 sit at the mouths of their burrows, but at any one's ap- 

 proach, rapidly ensconce themselves, making as they do 

 so a snapping noise. How the sound was produced Krauss 

 was unable with all his pains to discover. 



Athanas, Leach, 1814, differs in several respects from 

 the character of the family as given by Spence Bate in his 

 report on the Challenger Macrura, since the rostrum is 

 well developed instead of being reduced to a minimum, 

 the eye-stalks are only partially instead of entirely covered 

 by the carapace, and the first pair of trunk-legs, though 

 unequal in size, are not unsymmetrical in shape. The 

 first antennas have three flagella, the second a long ovate 

 scale with distal tooth. 



Athanas nitescens, Leach, is British, and is found also 

 in the Mediterranean. Spence Bate describes a new species, 

 Athanas veloculus, from the Cape Verde Islands. 



Parathanas, Spence Bate, 1888, is said to be closely 

 allied to Athanas, but to have on the first antennas only 

 two flagella, one of which is very short. The type species is 

 Parathanas decorticus, but to this is added Parathanas im- 

 maturus n. sp., founded on a specimen scarcely a fifth of 

 an inch in length, from which ' unfortunately all the pereio- 

 poda are broken off short.' It is spoken of as ' a damaged 

 specimen of what appears to be another species,' and the 

 Admissions are made that ' there is little to determine the 

 true character of the specimen,' and that ' the only dis- 

 tinguishable difference is that the rostrum is longer in 

 pioportion to the animal.' Since comparative measure- 

 ments in immature animals have no specific value, one is 

 tempted to transfer the ungallant observation about ' most 

 women ' to Parathanas immaturus, and say that ' some 

 species have 110 character at all.' 



Betatus, Dana, 1852, has no rostrum, and the 'hands ' 

 of the first legs more or less inverted, so that the finger or 

 seventh joint is 011 the outer instead of the inner side. In 



