OF THE ANTWERP CRAG. 389 
subtruncate in front, broadly rounded behind. End view very broadly subovate, emar- 
ginate in the middle both at base and apex. Surface of the shell irregularly furrowed 
or undulated in a transverse direction, and marked with distant pittings, which have a 
tendency to follow the lines of the furrows. Length 3'5 inch (0°66 millim.). 
One specimen only of this very distinct species has occurred in the Sables moyens 
(zone a Bryozoaires). 
CyTHerE LimicoLa (Norman). (Plate LXIV. figs. 9a, 9d.) 
Cythereis limicola, Norman, Nat.-Hist. Trans. Northumberland & Durham, vol. i. p. 20, pl. vi. 
figs. 1-4 (1865). 
Cythere nodosa, G. O. Sars, Oversigt af Norges marine Ostrac. p. 34 (1865). 
Cythere areolata, Brady, Trans. Zool. Soc. Lond. vol. v. p. 381, pl. xii. figs. 2 a-d (1865). 
Cythere complexa, Brady, Brit.-Assoc. Report, p. 210 (1866). 
Cythere limicola, Brady, Monog. Recent Brit. Ostrac. p. 405, pl. xxxi. figs. 38-41, 43-46 ; Brady, 
Crosskey, and Robertson, Monog. Post-tert. Entom. of Scotland, &c., p. 154, pl. x. figs. 1-4. 
Carapace, as seen from the side, subtrapezoidal, rather higher in front than behind ; 
height equal to about two thirds of the length; anterior extremity obliquely rounded ; 
posterior produced in the middle and excavated above ; superior margin rather concave, 
abruptly angular at each extremity, inferior nearly straight. Seen from above, the 
outline is boat-shaped, widest behind, tapering gently toward the front and abruptly 
behind. End view subtriangular, base broad and flat, apex obtusely rounded, sides 
excavated. Shell-surface uneven, rugose, often obscurely reticulated, the interstices 
being finely punctate ; a conspicuous rounded tubercle over the anterior, and two near 
the posterior hinge; a strongly marked longitudinal ridge runs along the valves just 
within the ventral margin. Length =? inch (0°54 millim.). 
_ One valve only found in the “Sables moyens” (zone & Isocardium cor). C. limicola 
is tolerably common in the North Sea in a living state, and has been found in many 
Post-tertiary deposits in Scotland, and also in Canada. 
CYTHERE LATIMARGINATA, Speyer. (Plate LXIV. figs. 8 a—8 d.) 
Cythere latimarginata, Speyer, Die Ostrac. der Casseler Tertiirbild. p. 22, pl. ili. figs. 3a-d (1863) ; 
Brady, Crosskey, and Robertson, Monog. Post.-Tert. Entom. of Scotland, &c., p. 163, pl. xvi. 
fig. 6. - 
Cythere abyssicola, G. O. Sars, Oversigt af Norges marine Ostr. p. 43. 
Carapace, as seen from the side, oblong, higher in front than behind ; height equal 
to about half the length; anterior extremity broadly rounded, posterior rounded but 
much narrower; superior margin sloping rather steeply backwards, and twice sinuated, 
in front of and behind the middle; inferior margin rather deeply sinuated in the 
middle. Seen from above, the outline is irregularly oval and compressed, the extremi- 
ties being wide and truncated; the sides only slightly convex, and marked by one or 
two rounded protuberances. The substance of the shell is very thick and hard; the 
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