210 POST-TERTIARY ENTOMOSTRACA. 



men ending in a long, slender process ; postabdominal lobes almost as in tlie preceding 

 genus. No eye. 



PsEUDOCYTHERE CAUDATA, G. 0. Sars. Plate II, fig. 9. 



PsEUDOCYTHEiiE CAUDATA, G. O. Sars. Overs. Norg. mar. Ostrac, p. 88. 



— — Brady. Monog. Rec. Brit. Ostrac, p. 453, pi. 



xxxiv, figs. 49 — 52 ; pi. xii, fig. d. 



Carapace of the male, as seen from the side, quadrilateral, highest in front ; greatest 

 height equal to more than half the length. Anterior margin broad and well rounded ; 

 posterior obliquely truncate, produced above into an obtusely conical beak ; superior 

 margin sloping in a somewhat sinuous line from before backwards; inferior slightly 

 sinuated in front, terminating behind in one or two small sharp teeth. The anterior 

 and ventral margins form a thin flattened lamina, which (in recent specimens) is marked 

 with radiating transverse lines, and is most strongly developed behind. Shell of the 

 female rather more tumid. Outline, as seen from above, compressed, tapering to the 

 extremities, which are slightly mucronate ; greatest width in the middle and equal to 

 one third of the length. Shell smooth, thin, and fragile ; pellucid. Lucid spots four, 

 linear, parallel, situated obliquely a little in front of the middle. 

 Length, s^th of an inch. 



Distribution. Recent. — Norway, Great Britain and Ireland. 



Fossil. — Scotland: Blackburn, Daliuuir, Raised-beach, Oban. Ireland: Woodburn. 



Genus 12 — Cytherideis, Jones. 



Carapace elongated, subovate, depressed in front ; hinge-margins nearly simple. Shell 

 smooth, punctate, sometimes grooved ; right valve overlapping the left in the centre of 

 the ventral aspect. Superior antennae slender, sparingly setose; last joint short and 

 bearing six short terminal setae ; penultimate and antepenultimate joints each bearing a 

 single apical seta. Mandible slender and curved, divided below into about four very 

 small indistinct teeth ; palp four-jointed, its first joint bearing on the inferior margin a 

 conical tooth-like process ; third joint set along its entire length with a comb-like series 

 of straight equal setae; in other respects like that of Cythere. First segment of the 

 maxillae much stouter and larger than the rest. 



