UllOTHOE BREVICORNIS. 199 



feature in U. marinus. The hands of tlie first two pairs 

 of legs are rather more slender, and have not the antero- 

 inferior margin of the wrist anteriorly produced, and 

 the hands have the palms more oblique, and still more 

 imperfectly defined. The third and fourth pairs of 

 legs, although armed with spines, are not so strong as 

 those of U, marinus. The dilated thigh of the fifth 

 pair of legs is almost triangular, and has not the pos- 

 terior margin crenulated ; the plumose hairs adorning 

 the posterior margin are reduced to a single tuft on the 

 carpus ; the finger is very long, and lias the anterior 

 margin entire, or imperfectly serrated. The last two 

 pairs are nearly uniform, and have tlie posterior margins 

 of tlie thighs imperfectly crenulated, and the fingers are 

 straight and styliform. The caudal appendages differ 

 from those of U. marinus in the greater length of the 

 base, and in the branches of the antepenultimate pair 

 reaching beyond those of the penultimate. The branches 

 of the ultimate are also shorter, and not fringed with 

 hairs. The middle tail-piece is long, naked, and obtuse. 

 This species was sent to us by our kind friend, Mr. 

 M. Webster, from Tenby, where he took it with the 

 dredge. 



