14 



nish in number as they ascend; and, as in the latter, are closely bordered 

 by granular tubercles. It should perhaps be considered as a variation 

 of C. papillata. 



Of Cidarites coronalis it is impossible to speak with decision, the spe- 

 cimens have been so rare and the descriptions so meagre. C. corollaris, 

 Plate I. Fig. 7, specimens of which have been so generally spoken of 

 among the early oryctologists, as ombria and ceraunia, is evidently, as is 

 very justly remarked by Leske, merely a silicious nucleus. These nuclei 

 vary in the figures and markings : they are all, however, rather orbi- 

 cular ; but some are much more depressed than others. But their dif- 

 ferences are not such as can at all oppose the opinion, that they are casts 

 of different species of C. miliaris or variolata. The large protuberance in 

 the middle of each side, is evidently formed by the excess of silicious 

 matter, beyond that which was necessary to fill the shell. 



With equal accuracy does Leske suggest, that the assumed genus of 

 Klein, of C. asterizans, does not merit the being considered as even a 

 distinct species: and 1 am happy in being able, I conceive, to point 

 out the genus, at least, to which this fossil may be referred; which 

 seems to be that of C. variolata. 



In the remarkably perfect specimen of a variation of C. papillata, 

 Plate I. Fig. 6, a view is obtained of the verrucous appendage, which, 

 in perfect specimens, is frequently found surrounding the superior open- 

 ing of the anocysti : of the use of which appendage, notwithstanding 

 the conjectures of Klein, it must be admitted that nothing is known. A 

 reference to this peculiar organization, it is hoped, will assist in explain- 

 ing the riddle which Walch and Leske, with M. Genzmer, have found 

 so puzzling. In Knorr's splendid work, Supp. x. a. Fig. 3, 4, is repre- 

 sented a fossil with its cast, which M. Walch considers, with M. Genz- 

 mer, as an echinus totally different from any with which we are 

 acquainted. There are in this fossil no tubercles, ambulacra, nor sutures, 

 as in other echini; but its surface is nearly covered with a kind of tre- 

 lisse work, formed by lines passing in almost every direction, so as to 



