Jones and Sherhorn — Tertiary Entomostraca. 451 



The specimens figured and described as C. angulatopora, in the 

 *'Monogr, Tert. Entom.," 1856, p. 34, are not referable to that 

 species. Figs. 17 and 18 of plate iv. correspond with the form (No. 

 33) to which we have here given the name C. scalaris; and fig. 18, 

 pi. vi. figured by Bosquet (we think, erroneously) as C. angulatopora 

 of Eeuss, we now regard also as a new species, and have named 



it C. BOSQUETIANA (No. 32). 



32. Cythere Bosquetiana, sp. nov. 



Cythere angulatopora (not Eeuss), Bosquet, Entom. Tert. 1852, p. 68, pi. iii. fig. 5. 

 Cythere angulatopora (not Eeuss), Jones, Monogr. Tert. Entom., 1856, p. 34, pi. vi. 

 fig. 18. 



One of the oblong species of Cythere, with rounded ends, well- 

 marked hinges, and convex valves, ornamented with a strong 

 reticulation, the longitudinal meshes of which are stronger than 

 the transverse. Just in front of the centre of the valve the meshes 

 show an inclination to assume a concentric arrangement. This is 

 strongly marked in fig. 18, pi. vi. of the Monogr. 1856. 



One valve, occurring with Nummulites elegans, in the " uppermost 

 bed" of the Bracklesham Series, at Hunting Bridge, New Forest. 

 Collected by Mr. Keeping. T. E. Jones' Coll. 



33. Cythere scalaris, sp. nov. PI. XI. fig. 7. 

 Cythere angulatopora (not Eeuss), Jones, Monogr. Tert. Entom., 1856, p. 34, pi. iv. 

 figs. 17, 18. 



Another oblong Cythere with nearly equal ends, but the front 

 margin, sloping to the strongly marked anterior hinge, is more 

 oblique than the other. The surface has longitudinal ridges, which 

 on the hinder moiety of the valve are connected by transverse riblets, 

 making irregular square meshes. The disposition of the ridges vary 

 as to their parallelism. 



A fine series of allied forms, from Gaas, near Dax, have been 

 described and figured by Eeuss ('Sitz. k. Ak. Wiss. Wien,' vol. Ivii. 

 1868, pp. 38-40, pi. vi. figs. 3, 4, 5, and 7) ; but the differences are 

 sufficiently apparent. 



Two or three examples, London Clay ; Islington. T. E. Jones' 

 Coll. 



34. Cythere polyptyoha (Eeuss), var. 



Somewhat trigonal-obovate ; the antero-ventral angle and the 

 opposite hinge both well developed. Anterior border nearly semi- 

 circular ; the posterior somewhat contracted. Surface puckered 

 with nearly parallel, but irregular, longitudinal ridges, with inter- 

 mediate rough, but obscure reticulation. The central region swollen 

 into a round boss. Except that this specimen is less quadrate, 

 possesses a boss, and is less distinctly reticulate, it closely resembles 

 Keuss' original figure, Haidinger's ' Nat. Abth.,' vol. iii. 1854, p. 83, 

 pi. X. fig. 22, from the Tertiary of Bohemia. 



This Cythere belongs to a group of which C. pusilla, Bosquet, 

 Entom. Tert., p. 85, pi. iv. fig, 7, may be taken as a type ; possibly 

 embracing th.e species referred by G. S. Brady, Trans. Zool. Soc, 

 vol. V. 1866, p. 376, pi. lix. fig. 10, to Eeuss' C. clathrata (which. 



