390 DR. G. S. BRADY ON THE OSTRACODA 
surface of the valves usually more or less beset with small circular pits (but sometimes 
quite smooth), and having a large central rounded tubercle; anterior and posterior 
margins produced into wide, thickened, and rounded lips, and fringed with numerous 
fine teeth, usually a large number in front, but only five or six behind. Length 3'5 inch 
(0°75 millim.). 
This is perhaps the most abundant of all the species found in the Antwerp Crag, 
occurring in great plenty in the Panopea and Pectunculus-beds, not quite so commonly 
in the sables 4 Bryozoaires, and is quite scarce in the Zrophon- and Lsocardium-beds. It 
is remarkable that the species has not been found in the English Tertiaries; and one 
specimen only is on record from the Post-tertiary deposit of Hopton Cliff, near Yarmouth. 
It occurs in a living condition in the northern portions of the North Sea (Norway and 
Shetland), also in the Gulf of St. Lawrence (Canada). 
CYTHERE WETHERELLII, Jones. (Plate LXIV. figs. 7a—7d.) 
Cythere wetherellii, Jones, Quart. Journ. Geol. Soc. x. p. 161, pl. ii. fig. 9; Tertiary Entomost. 
England, p. 26, pl. iv. fig. 15, and pl. vi. figs. 16a—-16d. 
Carapace, as seen from the side, subquadrate, much higher in front than behind, 
greatest height equal to nearly two thirds of the length; anterior extremity broad, 
obliquely rounded; posterior narrowed, subtruncate, scarcely rounded ; dorsal margin 
sloping steeply, and slightly arched ; inferior somewhat convex and with a slight sinuation 
towards each extremity. Dorsal aspect broadly ovate, widest behind the middle, width 
nearly equal to the height ; extremities produced into two broad mucronate processes, 
End view very tumid, ovate, width and height about equal. Surface of the shell 
beautifully and sharply reticulated, the reticulations angular (hexagonal or subhexagonal) 
and coalescing on the ventral surface so as to form longitudinal furrows ; each valve 
forms a sort of curved aleform ridge along the ventral margin; and there is a large 
tubercle in the situation of the anterior hinge-joint, forming a distinct angle or 
gibbosity. Length 3; inch (1:05 millim.). 
A few specimens only of Cythere wetherellii have occurred in the Panopwa-bed 
(Sables inférieurs). In England it has been found by Professor Jones in the “ Middle 
Eocene” of the Isle of Wight. 
CYTHERE TARENTINA, Baird. (Plate LXIII. figs. 1a-1d.) 
Cythere tarentina, Baird, Proc. Zool. Soc. 1850, Annulosa, pl. xviii. figs. 31-33. 
Carapace, as seen from the side, somewhat wedge-shaped, much higher in front than 
behind, the greatest height being equal to more than half the length, and situated very 
near the anterior extremity ; anterior margin broad and obliquely rounded ; posterior 
narrowed almost to a point; superior margin sloping steeply, especially at the hinder 
end, very slightly arched; inferior gently convex, with a slight sinuation near the 
middle. The outline as seen from above is rhomboidal, the extremities truncate ; the 
