THE TERTIARY FORMATION. 27 



specimen was also received from Mr. F. Edwards among his specimens of Entomostraca 

 from Barton. 



No. 5. Cythere striatopunctata, Roemer, sp. Plate V, figs. 6, 7 a — 7 c, 10. 



Cytherina striatopunctata, Roemer. Neues Jahrb. f. Min., &c., 1838, p. 515, t. 6, fig. 2. 

 Cytheee striatopunctata. Bosquet. Mem. Couron. Acad. Belg., xxiv, p. 62, t. 3, fig. 1. 



INCH. 



Length, Jj Middle Eocene : England and Europe. 



Carapace ovate, very convex, subcjdindrical, somewhat resembhng a walnut in 

 miniature; right valve (pi. 5, figs. 6, 10) less uniformly ovate than the left valve 

 (pi. 5, figs. 7 a), narrower, and more angular on the dorsal border ; anterior and 

 posterior margins of the valves usually denticulate : surface ornamented with deep 

 concentric furrows, curving round the anterior part of the valve, converging posteriorly, 

 and becoming more or less straight and parallel at the centre ; the furrows are crossed 

 at short intervals by slight ridges, connecting the stronger concentric ridges which 

 define the furrows, and forming unequal reticulation, each mesh of which is, for the 

 most part, pierced at its centre by a well-marked pit. 



M. Bosquet has examined the specimen on which C. pertusa, Roemer, loc. cit. t. 6, 

 f. 2, was founded as a species, and he regards it as the young of C. striatopunctata. 



Cythere striatopunctata is very abundant in the Barton Clay of the Hampshire Coast 

 (Middle Eocene), and is plentiful in equivalent deposits at High Cliff, on the same 

 coast. It occurs also at Bracklesham, and in a bed of sandy clay with green grains 

 (silicate of iron) at Alum Bay, Isle of Wight (numbered 29 in Mr. Prestwich's section, 

 ' Quart. Journ. Geol. Soc.,' ii. p. 257, t. 9), containing a small, depressed, undescribed 

 Nummulite,^ and belonging to the Barton series (Middle Eocene). 



M. Bosquet has found it in the *' Sables moyens," the " Calcaire grossier," and the 

 "Sables inferieurs" of France, and in the "Sable a gres calcifere" and the Lower 

 Tons-rian beds of Belgium. Roemer described it from the Paris Tertiaries. 



No. 6. Cythere consobrina, sjjcc. nov. 



INCH. 



Length, J„ Middle Eocene : Barton, Hants. 



Carapace elongate-oval, subcylindrical ; obliquely rounded in front ; contracted 

 1 See also 'Quart. Journ. Geol. Soc.,' viii, p. 334, note. 



