CUMACEA FEOM THE COPENHAGEN MUSEUM. 7 



B'. No transverse ridges on dorsal surface of carapace. 



a'. A prominent tooth at the posterior lower corner of the 



lateral enclosed area C. elegans, sp. n. 



b'. No tooth at the posterior lower corner of the lateral 



enclosed area C. similis, sp. n. 



b. Ridges not enclosing a quadrilateral area on the side of the 

 carapace. 

 A'. Dorsal crest of carapace with a sharp tooth near anterior 

 end. • 



1. Carapace with an oblique lateral ridge C. uniplicata, sp. n. 



2. No ridge on carapace C, unicornis, sp. n. 



B'. Dorsal crest of carapace unarmed. 



1. Carapace longitudinally ribbed C. costata Caiman. 



2. Carapace with a very prominent encircling ridge 



anteriorly C. cingulata, sp. n. 



3. Carapace with a single short oblique ridge laterally . . C. thumsoni, sp. n. 



4. Carapace with two subparallel oblique ridges laterally . C, biplicata, sp. n. 



5. Carapace with two widely divergent oblique ridges . . C. australis G. O. Sars. 



6. Carapace with three transverse ridges crossing the dorsal 



surface and uniting below C. sibogce Caiman. 



7. Carapace with three ridges laterally^ the two posterior 



uniting or dying out before reaching the mid-dorsal 



line C. triplicata, sp. n, 



Cyclaspis LONGiPES, sp. n. (Plate V. figs. 1-5.) 



Description of adult Female. — Total length o'l mm. 



The carapace is about two-sevenths of the total length, slightly compressed, its 

 vertical height less than two-thirds of its length. The dorsal edge is slightly keeled, 

 most distinctly so in front, and is hardly at all arched as seen from the side. Pseudo- 

 rostrum very short, the ocular lobe reaching quite to the tip. Antennal notch shallow, 

 widely open. Antennal tooth very sharp, almost spiniform. The ocular lobe is very 

 broad and prominent on the dorsal surface. 



First leg-bearing somite well exposed. The second has a slight dorsal keel. 



Abdomen a little longer than the cephalothoracic region ; the somites subcylindrical, 

 with lateral articular processes. 



Antennules rather long, the last segment of the peduncle longer than the preceding. 



The first legs are very long and slender, extending beyond the tip of the pseudo- 

 rostrum by nearly two-thirds of the length of the carapace. The basis is not 

 much more than half of the length of the distal segments together. The dactylus is 

 shorter than the propodus and longer than the carpus. 



The peduncle of the uropods is one and a half times as long as the last somite and 

 is finely serrated on the inner edge. The endopod is about two-thirds as long as 



