246 Part III. — Nineteenth Annual Report 



abdomen are produced backward into distinct tooth-like processes. The 

 caudal furca are moderately stout and rather longer than the last abdo- 

 minal segment (fig. 1). 



The antennules are short and seven-jointed, and also moderately 

 setiferous ; the first four joints are moderately large and tumid, but the 

 last three are very small; the second joint is armed with a short conical 

 tooth on its exterior aspect, and a stout and elongated plumose seta springs 

 from the interior distal angle of the fourth joint (fig. 2). The formula 

 shows the proportional lengths of the joints of the antennules : — 



Numbers of the joints, . . .1.2.3.4.5.6.7 

 Proportional lengths of the joints, . 13 . 7 . 16 . 9 . 4 . 4 . 9 



The antennae. — The primary branches of the antennas are three-jointed, 

 the joints, which are sub-equal in length, are moderately elongated, a 

 secondary four-jointed branch is articulated to the distal end of the first 

 and is nearly equal to it in length ; the last three joints of the secondary 

 branches are small and their entire length scarcely exceeds that of the 

 preceding joint. Both branches of the antennae are provided with a 

 number of plumose set® of moderate length (fig. 3). In Longipedia and 

 Canuella the antennae differ from those just described, not only in the 

 character of the basal joints and in the manner in which the secondary 

 branches are hinged to them, but also in the secondary branches, in both 

 being six- instead of four-jointed. 



The mandibles are moderately stout, sub-cylindrical, and truncate at the 

 apex, each mandible is armed with several coarse apical teeth, and pro- 

 vided with a well-developed two-branched palp ; the branches of the palp 

 are supported on a slightly tumid basal joint ; the terminal branch appears 

 to be uniarticulate, but the posterior branch is composed of about four 

 joints, the three end ones of which are minute, both branches are mode- 

 rately setiferous (fig. 4). 



The maxillae are each furnished with a distinct manducatory lobe 

 armed with several moderately long and awl-shaped apical spines ; the 

 palp is obscurely two-branched and turned toward the same side as the 

 manducatory process, it is also furnished with a number of slender and 

 moderately elongated setae (tig. 5). 



The first maxillipedes are robust and somewhat similar in structure to 

 those of Canuella (fig. 6). 



The second maxillipedes are smaller than the first pair, and are 

 apparently four-jointed ; the first joint is larger than the other three com- 

 bined, but the third and fourth are very small. These maxillipedes are 

 armed with several stout and spiniform marginal setae and two or three 

 elongated spines, two spines at the end and on the inner aspect of the 

 first joint have a fringe of minute hairs along the interior edge, while 

 another at the end of the second joint is lancet-shaped, and has both 

 margins of the distal half minutely serrated (fig. 7). 



The thoracic feet. — The first four pairs of thoracic feet are each com- 

 posed of two branches, and both branches are three-jointed. The outer 

 branches of the first pair are considerably more elongated than the inner 

 branches, and they are also more robust, they are armed with moderately 

 elongated, stout, and spiniform marginal and terminal setae ; a single and 

 somewhat slender plumose seta also springs from the inner margin of each 

 of the three joints of the outer branches, as shown in the figure (fig. 8). 

 The inner branches are not much more than half the length of the outer 

 ones, they are composed of three subequal and sparingly setiferous joints ; 

 the inner distal angles of the first and second joints are continued into 



