44 
R. NORRIS WOLFENDEN. 
anterior antennas nine-jointed, the exopodite of the posterior antennae like II. chelifer, 
but smaller, the second basal of the mandible like H. brevicornis (= II. 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 lias 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 II. brevicornis and more like II. 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 II. flexus, it differs in the size, 
which, in the latter species, is only ’64 mm. in length, compared with 1*5 in 
II. furcifer. 
