130 



7. C. calamaris. Spheroidal, rather depressed ; the 

 larger areas, with distant papillary tubercles, surrounded by 

 a granular surface ; two rows of tubercles in the smaller. 

 The ambulacra, with pores, in four divisions ; the spines 

 hollow, and possessing much of the structure of a quill. 

 Recent. Leske ap. Klein, Tab. xlv. fig. 1-4. 



8. C. radiata. Circular, depressed ; the vent surrounded 

 by plates forming a star of five angularly pointed rays, with 

 a foramen in the point of each ray. From each termination 

 of these rays proceed two other rays forming another star ; 

 these, being the ambulacra, are pierced with numerous 

 pores. The interstices, or areas, are filled with differently 

 sized tubercles. On the base is also a stelliform expansion, 

 in the middle of which are five semilunar openings. 



This is a large recent echinus ; Echinanthus major, Seba. 

 Komet groote, Phelsum. Leske ap. Klein, Tab. xliv. fig. 1. 



The following fossils appear to belong to this genus, but 

 their specific characters are not so obvious : 



9. Coronalis. Nearly hemispherical ; the areas alter- 

 nately wide and narrow, with scattered papillae ; the am- 

 bulacra flat, uniting at the top, and forming a flat space 

 round the vent. Fossil. Leske ap. Klein, Tab. viii. fig. A. B. 



10. Corollaris. Various siliceous nuclei have been placed 

 under this head which have doubtlessly belonged to dif- 

 ferent species of cidarites. Leske ap. Klein, Tab. viii, 

 fig. C. 



The fossil specimen, named cidaris asterizans, by Klein, 

 does not appear to deserve, as is justly observed by Leske, 

 to be considered of a different species, being a spathose 

 fossil of C. diadema, or of one of its varieties, the striae, in 

 the engraving, having been too much helped by the artist. 

 Leske ap. Klein, Tab. xlvi. fig. 5. 



GENU;J III. Clypeus. Of a roundish subconical form ; 

 the base rather concave ; the mouth beneath, nearly central; 

 the vent near the apex ; the ambulacra bowed, striated 



