122 THE VOYAGE OF H.M.S. CHALLENGER. 



comer somewhat projecting, the inner obsolete. The basal spine is comparatively small, 

 and quite smooth. The basal part of the flagellum almost equals the scale in length, 

 and is very slender, with the middle joint longest ; the terminal part does not attain the 

 length of the basal, and consists of only eight articulations. 



The anterior hp (PI. XXII. fig. 1) exhibits the usual structure. 



The posterior lip (fig. 2) has the terminal lobes of a somewhat rounded form, with a 

 small ledge-like projection at the outer edge. 



The mandibles (fig. 3) are rather strong, their masticatory part expanded in the 

 usual manner, the cutting edge (see fig. 5) divided into several acute teeth, and forming 

 also a well-defined molar tubercle. The palp (see figs. 3, 4) is comparatively small, not 

 nearly attaining the length of the body of the mandible, and has the terminal joint 

 lamelliform, as also provided along the inner edge with a dense row of ciliated bristles, 

 the outermost of which has the character of a strong spine. 



The first pair of maxilla (fig. 6) present on the whole a normal appearance, having, 

 however, the exognath somewhat large and expanded. 



The second pair of maxillse (fig. 7) are mainly characterised by the small size and 

 triangular shape of the terminal joint, or palp. The exognath, too, appears more fully 

 developed than in any of the preceding genera, constituting, as it does, a distinctly 

 projecting triangular plate, drawn out anteriorly to a very acute angle, and fringed along 

 the outer edge with a dense row of plumose setse. 



The maxillipeds (fig. 8) are exceedingly slender, though not particularly elongate, 

 scarcely reaching, when extended anteriorly, beyond the antenna! scale. Of the joints, the 

 meral is by far the longest, exceeding even in length the three outer ones taken together. 

 The terminal joint (see fig. 9) is relatively very small, and j)rovided with several slender 

 bristles, two of which issue from a ledge-like prominence at the outer edge. The 

 exopodite is remarkably elongated, reaching nearly to the tip of the meral joint, and in 

 size appreciably exceeds the true exopods on the legs. The epipodite, on the other hand, 

 is very small and lobular. 



The first pair of legs (fig. 10) are most powerfully developed, and much larger than 

 any of the others, exceeding, as they do, when fully extended, half the length of the 

 whole body. As a rule they exhibit, however, a strong geniculate bend, the terminal 

 part, comprising the three outer joints, being abruptly reflexed, and thus forming with 

 the remaining part a more or less acute angle. The proximal part of the leg generally 

 extending straight forward, reaches nearly to the tip of the autennular peduncle. Of 

 the joints, the meral and carpal are exceedingly elongate and almost naked, as also very 

 movably connected with each other, the meral joint being by far the larger of the two, 

 and tapering somewhat towards the apex. The carpal joint is very slender, and slightly 

 dilated at the extremity, where it has on both edges a few short bristles. The propodal 

 joint is about half as long and linear in form, and exhibits along both edges a regular 



