50 THE ENTOMOSTRACA OF 



No. 8. Cytherideis Barton ensis, spec. nov. Plate V, figs. 2 a> 2 b, 3 a, 3 b. 



INCH. 



Length, -fa Upper Eocene : Barton, Hants. 



Carapace oblong ; rounded in front ; rounded obliquely behind ; dorsal and ventral 

 borders straight, the surface of the valve suddenly sloping inwards at the latter border ; 

 most convex rather behind the centre ; surface smooth. 



Dorsal aspect elongate-sub-oval ; end-vieio sub-ovate. 



This species appears to be related to Bairdia [?] lavissima, Bornemann (' Zeitsch. 

 Deut. geol. Ges./ vii, p. 358, t. 20, fig. 6), and Cytheridea [r] papillosa, Bosquet 

 ('Entom. Tert.,' p. 42, t. 2. fig. 5). 



I have found Cythere {Cytherideis) Bartonensis only in the Barton Clay, where it is 

 apparently rare. 



No. 9. Cytherideis flavida, Midler, sp. Plate IV, figs. A a — 4 c. 



Cythere flavida, Midler. Entomostraca, p. 66, t. 7, figs. 5, 6. 

 — Latreille. Hist. Nat. Crust., iv, p. 253. 



— — Desmarest. Consid. Crust., p. 388. 



_ _ Bosc. Man. d'Hist. Nat. Crust., ii, p. 284. 



— — Baird. Mag. Zool. Bot., ii, p. 184 j Trans. Berw. Nat. Club, ii, p. 153; 



Brit. Entom., p. 168, t. 21, fig. 12. 

 Monoculus flavidus, Gmelin. Linn. Syst. Nat., p. 3001, No. 33. 



— — Fabricius. Ent. Syst., ii, p. 494. 



— — Manuel. Enc. Meth., vii, p. 725, t. 266, figs. 10, 11. 



— — Rees. Cyclopsed., art. Monoculus. 



INCH. 



Length, -^ 5 - Recent : Britain ; Europe. 



Pliocene : Suffolk. 

 Upper Eocene : Isle of Wight. 



Carapace elongate, cylindrical, tapering in front, arched on the back, straight or 

 gently incurved on the ventral border, rounded at the extremities, most convex 

 and obtuse posteriorly ; surface smooth or slightly papillate. [The specimen figured 

 illustrates the narrower and more curved variety of this form.] 



Dorsal aspect elongate-narrow-ovate ; end-view sub-orbicular. 



This species is near to Cythere arcuata, Miinster, and some of its varieties (see 

 Bosquet, ' Crust, foss. Limbourg,' p. 59) ; but its extreme convexity and the obtuse- 

 ness of the hinder end sufficiently distinguish it. Among its many other allies, it also 

 approaches Bairdia [?] mytiloides, Bosquet, in outline ; but wants its ornamentation. 



