Carapace sub-rectangular, with height : length ratio relatively small. The dorsal margin straight, ventral margin slightly angled convexly at two-thirds the length, maximum height coincides with this angle (C. rhynchena Habitus 1, C. rhynchena Habitus 3). The postero-ventral corner is bluntly right-angled. Sculpture consists of a criss-cross pattern in the antero-dorsal region and 4-5 deeply incised striae which run parallel to the ventral margin from just below the incisure almost to the posterior margin. Right asymmetrical gland opening at postero-ventral corner on a small prominence with, just dorsally, a supplementary group of gland cells. Left asymmetrical gland opens at postero-dorsal corner.
In both sexes, frontal organ spinous proximally but bare distally especially in the dorsal region (C. rhynchena 1, C. rhynchena 3). Male, capitulum spinous region is broadly triangular with characteristic ventral outline. Male first antenna "e" seta armature 50-60 pairs of flanged spines (C. rhynchena 4), "b" seta with a ridged pad and "d" seta a row of short hairs level with "e" seta armature. In both sexes the long terminal setae on the endopodite of the second antenna are sword-shaped.
Müller, 1906 hesitantly placed this species in the mollis group mainly on the basis of the "lateral gland cells", i.e., the supplementary gland cells opening just dorsal to the right asymmetrical gland. Poulsen, 1973 separated it off in his genus Paramollicia , but this, too, is something of a rag-bag genus.
Recorded from all oceans, in the Atlantic from 60°N-40°S, where it is often amongst the dominant species at depths of 600-900m. 1, 2, 3 (R.R.S. Discovery Map).
None designated; status of original material uncertain.
Original description based on material collected from 0°-31°N in the Atlantic, and 26°S-35°S in the Indian Ocean.