44 R. NORRIS WOLFENDEN. 



anterior antennae nine-jointed, the exopodite of the posterior antennae like H. chelifer, 

 but smaller, the second basal of the mandible like H. brevicornis ( If. fulvus), and the 

 exopodite scarcely half as long as the endopodite ; both rami of the maxillae are about 

 equal ; the first lobe of the anterior foot jaws has three bristles, the fourth lobe is long, 

 and its hook short, the posterior foot jaw is much thinner and weaker than in H. chelifer 

 and IT. brevicornis and more like PL flexus. The first feet have thin and weak terminal 

 claws, both rami of only two segments, and the endopodite is short, the joints of both 

 branches being broader than in flexus ; the endopodites of the second and fourth feet 

 are larger in proportion to the exopodites than in chelifer and brevicornis, and in the 

 fourth pair reach to the middle of the last joint of the exopodite ; the bristles on 

 the second endopodite joint are, however, two, instead of one as in chelifer ; the last 

 joint of the fifth feet is comparatively small, and is scarcely half so broad as this ; 

 its last joint has five, the process of the basal joint, four bristles. 



The striking feature of H. furcifer is the length of the furcal segments, which are 

 usually very short in this genus, and though related to PL flexus, it differs in the size, 

 which, in the latter species, is only '64 mm. in length, compared with 1'5 in 

 PL furcifer. 



