OF THE PURBECK FOEMATJOIf. 345 



Only one recent species is known (see above); found in tidal 

 rivers in the East of England. This genus was at first placed, with 

 the Cypridte with doubt, but afterwards referred more certainly to 

 the Cytheridaef. 



8. Metacypeis Fokbesii, and var. verettcosa, sp. et var. nov. (PI. 

 YIII. figs. 11-16.) 



Cypris striato-punctata, Eorbes (non Romer et Dunker), MS. 

 July 18, 1851 ; MS. July "I'd, 1854 ; LyeU's Manual Elem.' Geol. 

 5th edit. 1855, p. 295, fig. 337« ; Elem. 6th edit. 1865, p. 378, 

 fig. 371a. 



Cypris striato-punctata, Huxley and Etheridge, Catal. Coll. Foss. 

 Mus. P. G-eol. 1865, p. 254. 



Oypridea striato-punctata, H. Woodward, Cat. Brit. Foss. Crust. 

 1877, p. 89. 



Figs. 11-14 : length § millim. ; figs. 15 and 16, | millim. 



This is remarkably like M. cordata, G. S. Brady (jS"ature, I. c), 

 above referred to, but it is less convex, and is longer in proportion 

 to breadth (height) ; and it shows a strong tendency to become 

 tubercled. The ornamental pitting may be described in Dr. Brady's 

 words : — " Surface of the valves closely set with small rounded im- 

 pressions, which are arranged in longitudinal rows, running on the 

 ventral surface into interrupted furrows ; ventral surface deeply and 

 broadly sulcate along the greater part of the median line." We 

 may add that the lines of dots, in both cases (receut and fossil) 

 curve round on the front third of the valve, and in the fossil speci- 

 mens they have a slight local swelling or a tubercle for their centre. 

 The linear ornament curves round also (but less distinctly) behind, 

 parallel with the posterior border. Edge-view, subovate or bluntly 

 pyriform. End-view short, broad, ovate. 



As E. Forbes seems to have referred this species (sufficiently well 

 indicated in his letter to Mr. Bristow, see above, p. 314) erroneously 

 to Eomer's species, and as the surface character in both the recent 

 and this fossil species is striato-punctate, I do not hesitate to give it 

 a new name, dedicating it to the memory of the much-lamented 

 palaeontologist and geologist who worked out the three main divisions 

 of the Purbeck series, as characterized by the fossils, among which 

 especially were Ostracoda treated of in this paper. Prof. Dunker 

 agreed with me in regarding this species as quite distinct from 

 Oypridea striato-punctata (Edmer), which may, I think, be possibly 

 a variety of, or near ally to, C. valdensis or C. punctata. 



8*. M. FoRBESii, var. verrucosa. (Figs. 12 and 14.) 



Here we have the tendency towards tuberculation carried to the 

 fuU, that is, as far as yet observed ; and the individuals are not 



t Egger's Bairdia glutaa, from the Miocene beds of Mairhof, near Orten- 

 burg, in Lower Bavaria (•' Die Ostrakoden der Miocan-Scbichten," &c. in the 

 'Neues Jahrbuch f. Min.' &e. 1858, p. 408, pi. 1. fig, 6), has evidently the cha- 

 racters of this genus. 



