174 POST-TERTIARY ENTOMOSTRACA. 



2. LiMNicYTHERE? ANTiQUA, oiov. sp. Plate XVI, figs. 4, 5. 



Carapace, as seen from the side, oblong, subreniform, higher in front than behind, 

 height equal to half the length. Extremities well and evenly rounded, the posterior much 

 the smaller ; superior margin sloping almost in a right line from before backwards, 

 inferior deeply and suddenly sinuated in the middle ; seen from above, compressed ovate, 

 with slender acuminate extremities, greatest width a little in front of the middle, and 

 equal to one third of the length. Shells marked with a faintly striato-reticulate pattern 

 and with a bicurvate transverse furrow near the middle of the valve. 

 Length, ^th of an inch. 



It may perhaps be doubted whether this form be not referable to the young or some 

 local variety of the foregoing species ; its chief distinctive characters are the narrowed 

 posterior extremity, straight dorsal margin, and faint surface-sculpture, just such as are 

 usually presented by young shells, but we have not as yet seen any distinctly intermediate 

 forms, nor are we sure as to the young of the recent L. inopinata. 



Distribution. Fossil. — Scotland : Crofthead, Terally, Dipple. 



3. LiMNiCYTHERE Sancti-Patricii, Brady and Robertson. Plate II, figs. 1 — 3. 



1869. LiMNiCYTiiERE Sakcti-Pateicii, B. and R. Ann. Mag. N. H., ser. iii, vol. iv, 



pi. xviii, figs. 8 — 1 1 ; pi. xxi, fig. 4. 



Carapace (of the male ?), as seen from the side, reniform, nearly equal in height 

 throughout, height equal to half the length ; extremities well rounded, the anterior 

 slightly the broader ; superior margin almost straight, inferior deeply sinuated in the 

 middle. Seen from above, the outline is irregularly rhomboidal, widest somewhat behind 

 the middle ; extremities acuminate ; greatest width rather less than the height. Seen 

 from the front, the outline is widest at the base, with gradually converging sides and 

 broadly arched apex ; ventral margin convex, and prominently keeled in the middle. 

 Surface of the valves sculptured with small, closely set, polygonal excavations, and marked 

 across the middle with a conspicuous broad and deep curved furrow, in front of which 

 is another, of similar character, but smaller ; behind the posterior furrow the shell rises 

 towards the ventral surface into a prominent rounded eminence : the ventral surface is 

 furrowed in a longitudinal direction, and also marked more or less with cross striae. 



Distribution. Becent. — Great Britain, Ireland. 



Fossil. — England : Branston Pen, Lincolnshire. 



