25 



species. Dorsal face of shell flattened in its anterior half, or even somewhat 

 excavated, the excavation being defined on each side by an obtuse keel. Sur- 

 face of valves distinctly decussated by sharply marked striae crossing each other 

 and forming a very conspicuous net-work of quadrangular meshes, in some 

 places assuming a somewhat squamiform appearance; upper posterior corner 

 of each valve armed, somewhat within the edge, with 4 or 5 rather strong 

 deflexed denticles. Frontal tentacle more fully developed than in C. elegans, 

 with the extremity conspicuously club-shaped and finely hairy. Structure of the 

 several limbs very little different from that in the preceding species. Caudal 

 lamellae with the 3 anterior claws rather slender and elongate, the remaining 

 4 claws atruptly much shorter. 



Male of rather smaller size than female, and having the shell com- 

 paratively narrower and mr>re distictly sinuated below. Frontal tentacle with 

 the club-shaped extremity sharply defined behind, so as to form a well marked 

 capitulum. Outermost apical seta of the anterior antennae considerably longer 

 than the others and abruptly bent near the end, the middle part of the seta 

 being somewhat thickened and armed posteriorly with a dense series of recurved 

 somewhat squamiform spinules; posterior reflexed sensory filament tortuous 

 in a peculiar manner. Hook on the inner ramus of right posterior antenna 

 comparatively much larger than in the male of C. elegans. 



Shell in the living animal rather pellucid, with only a very slight pale 

 yellow tinge; enclosed body exhibiting in some places a bright reddish orange 

 pigment. 



Length of adult female amounting to 2.80 mm.; that of male scarcely 

 exceeding 2.30 mm. 



Remarks. The present species is easily distinguishable from the preceding 

 one, and has even by G. W. Muller been placed within a separate group of 

 the genus, the so-called mollis-group. I think however that such a sharp 

 distinction of these 2 species may scarcely be justified, as both on the whole 

 agree rather closely in almost all structuial details. Yet the specific difference 

 is well expressed both in the general outward appearance and in the sculpture 

 of the shell. 



The form recorded by G. W. Muller from the antarctic Ocean under the 

 name of C. antipodum, is closely allied to the present species, and has indeed 

 been regarded by Dr. Skogsberg as only a variety. The same belief Js also 

 expressed by that author as regards the arctic form, C. maxima, Brady & 

 Norman. I feel however greet hesitation in approving these views. 



Occurrence. This form was first detected by the present author off the 



4 Crustasea 



