30 CRETACEOUS ENTOMOSTRACA. 



1. PsBUDOCYTHEEE ? SIMPLEX, sp. nov. Plate II, figs. 58 — 60 ; and Plate IV, figs. 



37 and 38. 



PI. II, fig. 58. Length '8 ; height -32 mm. 



PI. II, fig. 59. „ -75; „ -3 „ 



PI. II, fig. 60. „ -57; „ -27 „ 



PI. IV, fig. 37. „ -9 ; „ -33 ; thickness '33 mm. 



Figs. 58 and 59 represent two right-hand valves ; they are suboblong, rounded 

 in front, angular behind, and produced at the postero-dorsal angle ; straight 

 on the dorsal and very slightly arched on the ventral border ; convexity slight, 

 greatest posteriorly. Edge view of united valves narrow-ovate, sharp above; 

 end view oval. 



Fig. 60 is a smaller left-hand valve, similar to the foregoing except that it is 

 more arched ventrally, and the postero-dorsal angle is but slightly produced (not 

 quite sufficiently expressed in the drawing). 



Many Gytherurse and BytJiocytherse have a more or less obtusely conical posterior 

 projection, but we think that this form agrees best with Pseudocythere. 



Locality. — Chalk, Horstead, Norfolk. 



IV. Cytheeuea, G. 0. Bars, 1865. 



See Monogr. Post-Tertiary Entom., 1874, p. 191. 



1. Cytheruea appendiculata, Jones. Plate III, figs. 17, 18. 



Ctthbeella ? APPENDICULATA, Joues. MoDogr. Eotom. Cret., 1849, p. 32, pi. vi, 



figs. 21a, h. 

 CYTHEErEA APPENDICULATA, Jones. Geol. Mag., 1870, pp. 76, 77. 



Length '69 ; height '36 ; thickness '27 mm. 



Unfortunately broken and lost, the unique specimen (from the Oault of 

 Folkestone) has not been replaced by any fresh discovery. 



V. Cytheropteron, G. 0. Sars, 1865. 



G. S. Brady, ' Eeport Challenger Ostracoda,' 1880, p. 135. 



This genus includes many species of diverse appearance, but with such 

 characteristics as we find also in the Cretaceous specimens under notice. The 

 valves are subrhomboidal and tumid, and variously sculptured. The ventral 

 region is swollen, and may be quite smooth, or bordered by a ridge, or marked 



