10 



Nat. History of Oxfordshire, PI. v. Fig. 5; and copied by Lister, de lapid. 

 turbin, Fig. 23. To this species he also refers the echinites figured by 

 Bourguet, Traite des Petrificatiom, Fig. 336, as well as some of the echi- 

 nites figured by Abilgaard and one or two others. C. hemispherica, 

 which is however very properly suspected by Leske to be only a variety 

 of Echinus esculentus, is, as was observed of that species, not a frequent 

 fossil : it is, I believe, depicted as such by Walch only, Monum. des Cat. 

 PL E. II. Fig. 1 ; and copied by Leske, Tab. XL. Fig. 7. C. angulosa 

 appears also to be depicted by Walch only, Monum. des Cat. PL E. II. 

 Fig. 5. The specimen is of the small variety. Leske describes and 

 figures a small echinite, a variety of this species, echinites excavatus, from 

 Verona. Another fossil from that place, which I possess, seems to be 

 another variety of C. miliaris saxatalis, apparently echinus gratilla, Linn. 

 Its characters are, ten ambulacra, with three rows of double pores, and 

 five broad and five narrow areae. 



The above are considered by Klein as comprised under the genus 

 miliaris, from their tubercles being of the size of millet-seeds. Those which 

 we have next to examine, he considers as a genus, which he names 

 variolata, from the size of the tubercles, and have been supposed to 

 resemble the Turkish turban. Cidaris diadema, of this genus, does not 

 appear to have been known to exist in a fossil state. 



The echinite, Plate I. Fig. 4, from Wiltshire, approaches, however, 

 very nearly to this species. It has ten areae : in the five larger are two 

 rows of tubercles; those just above the margin being large, and those 

 above and below these gradually diminishing. These tubercles are all 

 pierced in their apex, and have the margin of their base crenulated, as in 

 those of the next genus, and surrounded by a granulated surface. The 

 smaller areas project beyond the larger, and are formed of two rows 

 of miliary tubercles. The ten ambulacra are porous, each being formed 

 by two 'rows of pores disposed in pairs. 



The very uncommonly perfect specimen, from Stunsfield, Oxford- 

 shire, Plate I. Fig. 8, in which a considerable number of spines are still 



