CUMACEA FKO.M THE COPENHAGEN MUSEUM. 11 



is slightly curved upwards and outwards at the tip; the distal half of its inner edge is 

 strongly serrated and bears a single small pectinate spine. The exopod has a short 

 apical spine and a series of plumose setae on the inner margin. 



yhlult Male.— Total length 6-2 mm. 



The carapace is about two-sevenths of the total length, its vertical height not much 

 more than one-half of its length. The dorsal outline is less strongly arched than in 

 the female. The ridges defining the depressed area on the lateral surface are less 

 prominent. The tubercles at the two lower corners and that at the anterior upper 

 corner are well-marked, but there is no posterior upper tubercle, and the upper 

 horizontal ridge does not meet the posterior vertical ridge. Seen from above, the 

 carapace is not wider behind than in front. The ocular lobe and the corneal facets 

 which it bears are considerably larger than in the female. The antennal notch is 

 somewhat shallower, and the antennal tooth is slightly different in form. 



The first leg-bearing segment is entirely concealed. The second is as high as the 

 posterior part of the carapace. Its dorsal crest is rounded, not produced, and the 

 lateral plates are not expanded. The dorso-lateral keels of the last two thoracic and 

 the first two abdominal somites are more strongly developed than in the female. 

 As usual, the abdominal somites are much stouter than in the female. The fifth 

 somite is laterally constricted in its posterior half. 



The autennules are similar to those of the female, with a single additional sensory 

 filament springing from the end of the third segment. The antennae resemble those 

 of C. longicaudata as figured by Sar.«, except that the distal segment of the peduncle 

 is shorter and stouter and the setae clothing it are shorter. The branchial apparatus is 

 more fully developed than in the female, the lobules being about seventeen in number. 



The pleopods appear to differ from those of C. longicaudata in lacking the process 

 from the outer margin of the eudopod. 



The uropods are longer than in the female. The peduncle is about as long as the 

 last somite and is beset along the whole of its inner edge with plumose setae. The 

 rami are about equal in length to the peduncle, the inner slightly shorter, and resemble 

 those of the female except that the endopod, as well as the exopod, has its inner edge 

 beset with plumose setae. 



Young Stages. — In a specimen I-75 mm. in length (PI. II. fig. 5) there is no trace 

 of the last pair of legs. The integument is well-calcified and brittle. No corneal facets 

 are visible on the ocular lobe, and the lateral articular processes of the abdominal 

 somites are not yet developed. The first leg-bearing somite is entirely concealed. On 

 the side of the carapace the ridges bounding the depressed area are well-marked, but 

 of the four tubercles only the anterior upper one is prominent. 



Specimens about 5 mm. in length (PI. II. fig. 6) have assumed nearly the form of the 

 adult, but the first leg-bearing somite is still concealed. It is noteworthy that at this 

 stage the male resembles the adult female more closely than it does when full-grown. 



