OF THE ANTWERP CEAG. 403 



very small setae. Jaws as in Cythemra. Feet long and slender, terminal claws slender. 

 Abdomen ending in a long, narrow process ; postabdominal lobes bearing three short 

 hairs. Copulative organs of the male armed behind with three spiniform processes, 

 one of which is trifurcate. Eyes wanting. 



Cytheropteron latissimum, Norman. (Plate LXIX. figs. 1 a-1 d.) 

 Cythere latissima, Norman, Nat.-Hist. Trans. Northumberland and Durham, vol. i. p. 19, pi. vi. 



figs. 5-8 (1865) ; Brady, Trans. Zool. Soc. vol. v. p. 381, pi. Ixii. figs. 4«-e (1866). 

 Cytheropteron convexum, Sars, Oversigt af Norges marine Ostrac. p. 80 (1865). 

 Cytheropteron latissimum, Brady, Monog. Recent Brit. Ostr. p. 448, pi. xxxiv. figs. 26-30; Brady, 

 Crosskey, and Robertson, Monog. Post-tert. Entom. Scotland, &c. p. 202, pi. viii. figs. 19-23. 



Carapace, as seen from the side, subovate, highest in the middle, height equal to two 

 thirds of the length ; anterior extremity rounded, posterior rounded but angulated 

 above, scarcely beaked; dorsal margin boldly and evenly arched; ventral convex, 

 sinuated in front. Seen from above, nearly rhomboidal, greatest width behind the middle 

 and equal to two thirds of the length, extremities acuminate. End view equilaterally 

 triangular, sides convex. Surface marked with oblong pits, which are arranged in 

 flexuous transverse grooves ; ventral surface longitudinally furrowed ; lateral alseform 

 process rounded and not very prominent. Length -^ inch (0-60 millim.). 



This species is widely distributed in the present day over the North Sea, and as far 

 as BaiEn's Bay and Spitzbergen. It occurs commonly as a fossil in the Post-tertiary 

 beds of Scotland, at Bridlington in England, and also in Canada. The specimens here 

 described are from the Pano^wa-hed (Sables inferieurs), and the zone a Bryozoaires 

 (Sables moyens). 



Cytheropteron intermediuai, nov. sp. (Plate LXIX. figs. 3 a-3 c.) 

 Carapace, as seen from the side, oblong, rounded in front, produced behind into a 

 broad obtuse median beak; dorsal margin moderately arched, ventral nearly straight. 

 Seen from above, rhomboidal, greatest width situated behind the middle, and equal to 

 two thirds of the length ; the lateral margins end abruptly in a rectangular projection 

 behind the middle, the hinder third of the shell being much narrower, and forming 

 an acutely tapering process ; the anterior extremity is also sharply pointed. End view 

 triangular, with nearly straight margins and acute angles. Surface of the shell slightly 

 furrowed transversely, otherwise smooth. Length -g-Q inch (0-50 millim.). 

 A few examples only were found, in the Pano^cea-hed (Edeghem). 



Cytheropteron gradatcm (Bosquet). (Plate LXIX. figs. 4a -4 d.) 

 Cythere gradata, Bosquet, Entom. fossil, terr. Tertiair. France, &c. p. 127, pi. vi. figs. 11 a-d (1852). 

 Cythere papilio, Egger, Ostrak. der Miocan-Sch. Orenburg, p. 42, pi. vi. fig. 9. 

 Cythere bilacunosa, Speyer, Die Ostrac. Casseler Tertiiirbild. p. 34, pi. iv. fig. 6 (1863) . 



Carapace, as seen from the side, oblong, quadrangular, slightly higher in front than 

 VOL. X. — part viii. No. 4. — August 1st, 1878. 3i 



