Jones and Sherboni — Tertiary Entomostraca. 455 



one is here figured, differ individually from those previously figured 

 in the Monogr. 1856, and elsewhere, in their narrowness, the paral- 

 lelism of their upper and lower margins, and in the replacement of 

 the curved dorsal ridge by a uniform marginal rim. The very faint 

 markings seen along the ventral ridge, in the figures in the Monograph 

 of 1856, are more distinct in the specimens now under consideration, 

 and are evidently due to alternate thick and thin rod-like divisions, 

 forming minute, light and dark, squarish areas. The slight trans- 

 verse dorsal notch in fig. 19 is also traceable in our present specimens, 

 when carefully illuminated and strongly magnified. 

 Bracklesham. T. E. Jones' Collection. 



45. Cytheridea pekfokata (Eoemer). 



This specimen is like figure 14a, pi. iv. in the ' Monogr.' 1856, but 

 is rather less triangular, much more coarsely punctate and strongly 

 marked at the front hinge. 



It was found with numerous normal valves in some washings from 

 the clay at Barton. 



T. E. Jones' Collection. 



46. C"STHEKIDEA PERFORATA, var. INSIGNIS. PI. XL Fig. 12. 

 Monogr. Tert. Eutom., 1856, p. 46, pi. vi. fig. 3. 

 This fine variety is reproduced in the accompanying Plate from 

 the original monograph. It was found in the London Clay of Copen- 

 hagen Fields. 



47. Cytheridea glabra, Jones. PI. XL Fig. 13. 



Cytheridea perforata, var. glabra, Jones. Monogr. Tert. Entom., 1856, p. 46, 



pi. V. fig. 24. 



This angular and smooth form, related to C. perforata, should now, 

 we think, be regarded as a species. It came from the London Clay 

 of Copenhagen Fields. 



48. Cytheridea ptjnctillata, Brady. 



One damaged valve we refer to this species, which has been 

 described and figured in full in the ' Monogr. Post-Tertiary Entom.,' 

 1874, p. 177, pi. vi. figs. 1-11. Our specimen, however, approaches 

 most closely to another figure of the same species in Dr. Gr. S. Brady's 

 paper, ' Trans. Linn. Soc.,' vol. xxvi. (18G8), p. 424, pi. xxvi. fig. 36. 



From the " Norwich Crag " at Southwold. T. E. Jones' Col- 

 lection. 



49. Cytheridea pinguis, Jones. 



We have this species from the Wey bourn Crag ; collected by Mr. 

 Clement Eeid at East Eunton. Dr. Gr. S. Brady figures it from the 

 Antwerp Crag, ' Trans. Zool. Soc.,' vol. x. p. 397, pi. Ixii. fig. 3. 



50. Cytheridea debilis, Jones. 



We have seen a right valve (opposite to that figured in the 

 Monograph, 1856), apparently belonging to this species from the 

 Belosepia-Bed, Bracklesham. Science Schools Collection. 



