REPORT ON THE CUMACEA. 29 



The peduncle is geniculate in the middle, the two outer joints almost forming a right 

 angle with the two inner ones. The third joint is the smallest and provided with two 

 strong hairy setae and a little dentiform projection. The fourth joint is linear and armed 

 along the outer edge with a row of five small denticles. The nagellum forms a very 

 slender and narrow joint, about half as long as the peduncle, and provided at the tip 

 with four delicate auditory bristles. In the young male the antennae (see PL III. fig. 14) 

 exhibit the usual appearance, being strongly geniculate at the base and reflexed beneath 

 the carapace. The proximal part of the peduncle is provided with four strong ciliated 

 setae curving anteriorly; the distal part of the peduncle is smooth and composed of two 

 well-defined segments, the outer one the larger. The nagellum has the appearance of a 

 densely annulated vermiform appendage, slightly flexuous, and as yet quite smooth, 

 terminating in an obtuse point. 



The anterior lip (PI. II. fig. 11) forms a semi-oval fleshy prominence, slightly emarginate 

 at the tip, with the free edge densely ciliated. 



The posterior lip (fig. 12) is quite membranous, its lateral lobes rounded, triangular, 

 and terminating in a somewhat incurved, densely ciliated corner. The inner edges of 

 the lobes are also ciliated throughout their whole length. 



The mandibles (fig. 13) are well developed and similar in structure to those in the 

 genus Cyclaspis, as described above, though somewhat stouter and with the body com- 

 paratively shorter. 



The first pair of maxillae (PI. III. fig. 3) are markedly distinguished by the total 

 want of the usual reflexed palp, of which not even the slightest trace could be found by 

 the most careful dissection of several specimens, both males and females. No other form 

 of Cumacea hitherto known wants this part. In other respects, however, these maxillae 

 do not exhibit any marked peculiarity in their structure. 



The second pair of rnaxdlse (fig. 4) present quite the usual appearance. 



The maxillipeds (fig. 1, mp ; figs. 5, 6) are rather short and stout. The basal joint, 

 as usual, juts out at the end on the inner side as a linguiform masticatory lobe, having 

 along the inner edge a row of ciliated bristles, and at the tip several short dentiform 

 spines. The meral and carpal joints are broad and laminar, the former provided at the 

 outer edge with a strong ciliated seta, the latter with two somewhat smaller ones ; the 

 inner edge of this joint is also provided with a row of curved spinules, which are 

 denticulated at one of their borders in a comb-like manner (fig. 5, a), as also with 

 numerous simple bristles. The propodal joint becomes suddenly much narrower and 

 strongly incurved, bearing at the end internally two ciliated setae, and externally a bunch 

 of somewhat more slender bristles. The terminal joint is very small and linear, with 

 three small spines at the tip. 



The structure of the branchial apparatus in this form (see fig. G) would seem to 

 corroborate the supposition set forth by the author at an earlier date, but not adopted by 



