220 "TERRA NOVA" EXPEDITION. 



unsegmented portion. The proximal segmented portion would appear to be formed of 

 four somites. The suture marking off the first segment is visible in the middle line, 

 and on each side just behind the junction of the seventh thoracic tergum with its coxa 

 but not in between, nor does it extend to the lateral margins. The two succeeding 

 sutures are incomplete in the mid-dorsal line, but extend to the lateral margins. The 

 suture marking the fourth somite is complete. The posterior margin of the fourth 

 segment is produced backwards into a broad stout process the apex of which is 

 truncate or even slightly emarginate in dorsal view. On each side there are two small 

 processes or tubercles, the outer of which is the larger. The unsegmented terminal 

 portion of the abdomen has a single prominent lateral tubercle on each side above the 

 base of the uropods. The apex is trilobed, the median tongue-like process only slightly 

 shorter than the lateral ones. On the dorsal surface of the median lobe, at its base, is a 

 short, blunt, forwardly directed tubercle, which in dorsal view shows two quite small 

 tubercles, one on each side of its base, giving the whole a trident-like form. 



Uropods (pi. VI, fig. 7) with the endopod fused to the sympod, the whole forming 

 a stout rigid bar the inner edge of which is grooved and fitting over and under the 

 lateral margins of the abdomen in the familiar groove and tongue fashion known to the 

 carpenter. The outer uropod is much smaller than the inner, with its apex acute. 



Epistome of the form shown in pi. VI, fig. 3, very prominent both laterally and 

 dorsally. 



Antennules (pi. VI, fig. 4) reaching the posterior margin of the second free 

 thoracic somite ; basal joint of the peduncle rather broad, second joint small, third joint 

 as long as the first but much narrower ; flagellum composed of about eleven or twelve 

 joints. 



Antennae (pi. VI, fig. 5) a little longer than the antennules ; joints of the peduncle 

 all narrow except the first small joint, fifth joint the longest ; flagellum of about sixteen 

 to eighteen joints. 



Second thoracic limbs (pi. VI, fig. 6) much shorter and stouter than any of the 

 others, the merus, carpus and propodus all armed with stout spines, the dactylus 

 bi-unguiculate. 



In the succeeding thoracic limbs the merus is not so stout and is without strong 

 spines, the carpus and propodus successively becoming longer and the dactylus 

 bi-unguiculate. 



The processes on the sternum of the seventh thoracic somite of the male are rather 

 Ions and lie close to one another. 



The pleopods are of the usual hemi-branchiate type. The stylet on the second, 

 pair is longer than the rami, strongly curved, and acute at the tip (pi. VI, fig. 8). 



Of all the species of Cymodoce hitherto described, this species approximates most 

 closely to C. australis, Hodgson, described from specimens taken on the " Southern 

 Cross " Expedition in 8 fathoms, ofi" Cape Adare. It is indeed very closely allied to 

 the latter, and I hesitated for a long time whether to describe it as a new species. 



