PLATE CXXX\r* 



Echinus SuBDEPRESSUS : ovato-elliptica, dorso convexiuscula 5 

 lateribus subsinuosis; ambulacris ovato-oblongis, 

 pulvinatis ; ano margini vicino 



ill itmv 



ScuTELJUA Ambigena, Scutelle ambigene. Lamarck An. sans^ 

 Vert, 3. p. 1^. 



"•fa' " 



Echinus Rosaceus var ^. GmeL T. 1. p. 6. 3187. „ , 



•8 axiCBg adT 



This curious species of the depressed kinds of the Linnaean^ 

 gjenus Echinus, is nearly allied in its general appearance to his 



Echinus rosaceus, a species not uncommon, and which must bfe 



SIM. sill si 



therefore generally known. 



The Echinus now before us is one of those which has been 

 described by authors as the presumed varieties of the species, 

 rosaceus, all which, in a greater or less degree, appear to us 

 materially different ; the kind at present under our consideration, we 

 cannot in particular avoid believing to be specifically distinct^ 

 Lamarck has already admitted this ; that author has indeed so far 

 separated those two analogous species as to refer them to different 

 genera ; the kind before us is his Scutella ambigefia ; and the Lin- 

 nean Echinus rosaceus, hitherto regarded as the type of the species 

 constitutes with him the first species of his following genus Cltf' 

 peaster, Lamarck observes that the present species approaches very 

 nearly to the Clypeasters, and we cannot but conceive that where 

 the distinctions approximate so nearly, the differences ought scarcely 



