36 CRETACEOUS ENTOMOSTRACA. 



3**. Cytheeopteeon alatum (Bosquet), var. fortis (vel alaf/um -forte). Plate II, 



figs. 20, 21. 



Fig. 20. Length I'O; height '48 mm. 



Fig. 21. „ -96; „ -48 „ 

 This differs from Bosquet's type in being rounder in front and having the wing 

 further forward on the ventral region, with its posterior edge only slightly 

 spinose ; and the coarse denticles on both the front and hind margins of the valve 

 complete the varietal differences. It is not represented in any figures yet 

 published ; but Kafka's figs. 36 a, 6, at p. 16 of Fritsch's ' Crustac. bohm. Kreidef.,' 

 1887, described as Bosquet's Gythere serratula, is very near to it. 



Localities. — GhaU\ Horstead, and Whiteabbey and Magheramorne (Antrim). 



3***. Cytheeopteeon alatum (Bosquet), var. cornuta (vel alatum-cornutitm). 



Plate IV, fig. 36. 



Cytueh^ co'B.^VT A (Rd?7ier ?), Bosquet. Mem. Cour. Acad. Sci. Belg., vol. xxiv, 



1852, p. 117, pi. vi, figs. 4< a — d; and 

 Eeuss, Zeitsch. d. g. G., 1855, p. 212, 

 pi. X, figs. 10 a, b. 



Length 1*1 ; height '53 mm. 



An elongate oblong valve, almost equally rounded and denticulate at the ends, 

 rimmed in front, and bearing a short, angular, ventral wing, which reaches 

 scarcely beyond the middle of the valve, leaving the posterior third depressed 

 and bare. 



Except in the shortness of the wing, this form comes close to Bosquet's figure 

 of Romer's Gytherina cornuta} 



Localities. — Chalh, Kent ; and ? Chalk-rock, Dunstable. 



4. Cytheeopteeon Hibeenicum, sp. nov. Plate II, figs. 22, 23. 



Cttheee (Ctctheeeis) alata, Jones. Syst. Lists, &c., Belfast Nat. Field Club, 



vol. i, Appendix iii, 1875, pp. 81, 92. 



1 Cythereis cornuta (Romer ?), Jones, ' Monogr. Tert. Entom.,' 1857, p. 39, pi. iv, fig. 19, and 

 pi. V, figs. 15 a, h, is possibly a Cytheropter-on near C. alatum ; but the Cythereis cornuta of tbe ' Suppl. 

 Monogr. Tert. Entom.,' 1889, p. 35, pi. i, fig. 22, is regarded by Dr. Gr. S. Brady as an undeveloped 

 or young form of Cythereis Jonesii, Baird (see ' Trans. 11. Dublin Soc.,' ser. 2, vol. iv, p. 169). 



