the specific name proposed alludes to this ornament, which somewhat res- 

 embles that found in Cytheridea papillosa (see above). 



Occurrence. I have only had an opportunity of examining a single living 

 specimen of this form, found, many years ago, in the upper part of the Chri- 

 stiania Fjord; but several empty shells were picked up by my late father from 

 shell-sand taken at 0xfjord, Finmark. 



Distribution. British Isles, Gulf of St. Lawrence. 



Fossil. Norway, Scotland, Canada. 



72. Eucythere declivis, (Norman). 



(PI. LXXV, fig. 2). 



Cythere deslivis, Norman, Nat. Hist. Trans. Northumb. & Durham, Vol. 1, p. 16, PI. V, 



figs. 9-12. 



Syn: Cytheropsis tenuitesta, G. O. Sars. 



Specific Characters. Female. Shell, seen laterally, short triangular in 

 shape, very high in front and rapidly tapered behind, greatest height almost 

 attaining 3 /5 of the length, dorsal margin gibbously arched in front and sloping 

 rather sleeply behind, ventral margin very slightly sinuated, anterior extremity 

 broadly rounded, posterior narrowly blunted; seen dorsaily, oblong ovate in 

 outline, greatest width behind and much less than the height, anterior extre- 

 mity tapering to an acute point, posterior obtuse. Valves very thin and pel- 

 lucid, with the surface finely punctate and provided with scattered rather small 

 papillae. Anterior antennas more slender than in the preceding species, with 

 the distal segment of the basal part less prolonged, last joint exceeding half 

 the length of the preceding joint. Posterior antennae less robust, with the 

 terminal joint smaller, anterior apical claw smooth. Maxillae with the inner- 

 most masticatory lobe bisetose, distal joint of palp longer than the proximal 

 one. Legs more slender than in E. argus, and more rapidly increasing in 

 length posteriorly; apical claw very long. 



Male. Shell considerably more elongate than in female, seen laterally, 

 narrow clavate in outline, tapering behind to an obtuse corner. Copulative 

 appendages of comparatively simple structure, terminating in a rounded lobe 

 with thickened margins. Brush-like appendages very large, flabelliform, each 

 appendage being expanded at the end to a rounded disc densely edged with 

 curled bristles. 



Colour of shell not yet ascertained. 



Length of adult female 0.58 mm., of male 0.62 mm. 



