120 



Scutella, the first genus, comprises placenta of Klein 

 ( echinodiscus of Breyn and Leske), and echinarachnius of 

 Klein and Leske. 



The admission o^ echinarachnius within the limits which 

 Lamarck has prescribed to this genus cannot be allowed. 

 The ambulacra, extended only to the margin, and the mouth 

 placed on the upper side of the margin, must exclude it 

 from a genus, comprized in a section, the members of which 

 are described as having the ambulacra complete, and the 

 mouth beneath the margin. Of the name of the genus, it 

 may be observed that it is not more expressive than that 

 which it is proposed to supersede ; and is, besides, the 

 diminutive of the word (scutum), by which another widely 

 different genus has been designated. 



Clypeaster is a new, but does not appear to be a more 

 distinctive, name for this genus, than scutum of Klein, or 

 echinanthus of Leske, Breyn, &c. 



Fihularia is proposed as a denomination preferable to 

 that of echinocyamus, which had been adopted for this 

 genus by the assiduous Phelsum. No reason, however, for 

 this preference appears, and the term, fihularia.^ is so far 

 objectionable, as it resembles fibula employed by Klein, 

 with equal propriety, for a section including echini of very 

 different characters. 



Echinoneus is applied in the same manner as by Phelsum 

 and Leske. 



Galerites is assumed as appropriate to the genus, the 

 first species of which is conulus albo-galerus of Klein, and is 

 followed by those other fossil echini to which have been 

 applied the more apt name of conulites. 



Ananchytes is employed in the place of cassis of Klein, 

 or of echinocorites of Leske. 



Spatangus is applied nearly in the same 'manner as b}^ 

 Leske ; its species are divided into those with four and 

 those with five ambulacra. 



