FROM THE G/VULT AND GREENSAND. 37 



cannot be given. In Cidaris vesiculosa, Goldf., the marginal circle of areolar tubercles 

 is not so prominent as in Cidaris Gaulfina, Forb., but the general character of the 

 ornamentation on the plates is the same in both. The spines figured by Goldfuss 

 closely resemble those of C. Gaidtina ; they have the same slender, elongated form, and 

 fluted structure ; most of them are spindle-shaped, and some have an expanded cup-like 

 termination, like the spine fig. 4, a. 



Locality and Stratigraphical Position. — Cidaris GauUina is a very rare urchin. I 

 only know the specimens contained in the Museum of the Royal School of Mines, and the 

 subject of our figures, which belongs to the British Museum ; both these fossils were 

 obtained from the Gault at Folkstone. Cidaris vesiculosa, Goldf., on the contrary, has 

 been collected from the Chalk-marl of Germany, and the Grey Chalk at Dover. 



B. — Species from the Upper Greensand. 



Cidaris velifera, Bronn. PI. II, fig. 2 a, b, c, d, e,f; fig. '6 a, b ; fig. 4 a, b. 



Cidaris VELirERA, Bronn. Jahrb., p. 154, the name only, 1835. 



— pisiFERA, Agassiz. Catalogus Systematicus, p. 10, 1840. 



— VELiFER, Bronn. Index Palceontologicus (" = iSa/e^iVe sp."), 1848. 

 — ■ MicHELiNi, Sorignet. Ours. Foss. de I'Eure, p. 18, 1850. 



— GLOBICEPS, Qwenstedt. Handbuch der Petrefactenkunde, p. 577, pi- 49, 



fig. 17, 1852. 



— VELIFERA, Woodward. Mem. Geol. Surv., Decade v, pi. v, 1856. 



— Heberti, Besor. Synopsis des Echinides Fossiles, p. 12, 1858. 



— velifera, Desor. Ibid., p. 34, 1858. 



— — Cotieau. Paleont. rran9aise ; Echinides, pi. 1054, figs. 14 — 21, 



p. 241. 



Test small, circular, depressed ; ambulacral areas narrow and sinuous, with four rows 

 of granules; inter-ambulacral areas wide, tubercles large and prominent, gradually 

 increasing in size from the peristome to the apical disc, where they are globose and con- 

 spicuous ; spines short, stems large and globular, surface covered with longitudinal rows 

 of pustular elevations. 



Dimensions. — Height, three tenths of an inch ; transverse diameter, eleven twentieths 

 of an inch. 



Bescriptioti. — This beautiful little Cidaris is one of the oldest representatives of the 

 group possessing claviform spines, Sadioli j/latidarii, for all doubt about the identity of the 



