195 



short and clumsy shape of the shell and by its strongly spinous armature. It 

 is one of the largest forms of known Cytheridae. 



Occurrence. I have taken this form occasionally in the upper part of the 

 Christiania Fjord in depths of 30 to 50 fathoms, muddy bottom, and also off 

 the Lofoten islands, where it descends to the considerable depht of 300 fathoms. 

 Norman records it also from some localities on the western coast of Norway. 



Distribution. Great deeps of the Atlantic (Challenger Expedition). 



95. Cythereis dunelmensis (Norman). 

 (Pi. xe.) 



Cythere dunelmensis, Norman, Nat. Hist. Trans, of Northumb. & Durham, Vol. I, pag. 23, 



PI. VII, figs. 14. 



Syn: Cythereis Iwrrida, G. O. Sars. 



Specific Characters. Female. Shell, seen laterally, oblong quadrangular 

 in shape, rather higher in front than behind, greatest height somewhat exceeding 

 half the length, dorsal margin strongly prominent in the ocular region and 

 sloping gently behind at nearly a straight course, ventral margin slightly sinuated 

 in the middle, anterior extremity broadly rounded, posterior rather narrower and 

 nearly transversely truncated, upper corner well marked, lower rounded off; 

 seen dorsally, rather regularly oblong oval in outline, with the greatest width 

 about in the middle and somewhat less than half the length, both extremities 

 obtusely pointed and nearly equal. Surface of valves evenly convex but armed 

 with numerous clumsy spines of somewhat unequal size and irregular shape, 

 some of them arranged more regularly in a curved series near the anterior 

 extremity, edges of the latter fringed with a likewise regular row of somewhat 

 spatulate denticles' successively increasing in size downwards, posterior extremity 

 with spines of somewhat varying shape, some of them, at the infero-posteal 

 corner, rather prolonged; hairy coating rather sparse. Sculpture of valves 

 distinctly reticulate. Eyes very large and conspicuous, with a glittering lustre. 

 Anterior antennas with the terminal joint rather prolonged, though scarcely 

 atfaining the length of the 2 preceding joints combined. Posterior antennas 

 with the penultimate joint less slender than in C. echinata, flagellum very short. 

 Legs moderately slender, with the 1st joint of the terminal part clothed in front 

 with fascicles of thin bristles. 



Male of about same size as female, but having the shell conspicuously 

 narrower and more elongate in shape, some of the spines on the hinder part 

 of the ventral face being arranged on each side in a pretty regular series well 



