36 



rayed star round the mouth. The anus is round, and placed in the 

 upper part of the acute extremity of the shell. 



One of these fossils, from St. Peter's mountain, is delineated Plate III. 

 Fig. 6. 



Echinites lapis caneri. Tab. XLIX. Fig. 10, 11, Lesk. This name was 

 given by Leske, from a supposed resemblance to the stones commonly 

 called crabs'- eyes. The shell is obtusely oval ; in the vertex, which 

 is excentrical, are four pores; and there meet five biporous, ovato-lan- 

 ceolated, petalloidal ambulacra, divided at their points. The base is 

 slightly excavated ; the month is in the centre, but nearer to the nar- 

 row end ; the anus is oval, and raised on the broader end, in the upper 

 part of a rounded groove. Plate III. Fig. 7, represents a specimen, 

 which, I have reason to believe, is from Switzerland. 



Echinites patellaris, Tab. LIII. Fig. 5, 6, 7, Leske. This species, which 

 is smaller than the preceding, is described as differing from all others, 

 except as to the mouth and anus, which agree in their situation with 

 those of the two last species. The difference appears chiefly to consist 

 in the shell being considerably depressed, and the ambulacra being dis- 

 posed in the form of a star. The shell is ovate in its periphery, the 

 back is slightly convex, and the base gently hollowed. 



I do not know if the curious echinite, Plate iv. Fig. 10, from Verona, 

 has been yet described. It is very flat, of a rude sub-cordate form, and 

 possesses a finely-granulated surface, which seems to be so formed by the 

 points to which the minute spines have adhered. I must however 

 acknowledge that 1 have only been able to discover one aperture in this 

 fossil, which is in its margin. 



