Page. 



[). ECHINUS LiXULA L. Pl. 3 -.. 80. 



The genus Arbacia Gray 81. 



The e])istron).i, PL J-^V _ 8G. 



Arbacia IJxnl.a 1... ..- 97. 



It8 habitat -.. • 101. 



The sjieeies of Arbacia 105. 



C. KriiiNrs SAXATii.is Ij 12 



7. EoiiiNUS DiAiuoMA L. Pl. 4.. 124. 



Deseriptions eoiiibined 12(). 



Siipplemental dcsoriptioii , 131. 



Diiuleina saxatile L 1?)5. 



Etliinotiix l)ia«1eiiia 1 _. 1?.7. 



8. F.ciiiNUs Cir»Ai;is L. /'/. ') \?t>^. 



Cidaris baculosa Lamck 144. 



Cidaris iuiperialis Lamck. 147. 



Cidaris tennispinis Tknyson-Wooos 148. 



0. ECHINUS MAMII.LATrS L ._. 150. 



Hpterocentnis inaiiiillafiis \, 151. 



10. EcillNUS LUCUNTER L. 153. 



Ecliinometra Liicuiiter L 157. 



11. ECHINUS ATRATTS L 158. 



Colobocentrns atratiis L __. » 



12. Ei'Hi\uR Spataous E. Pl. 6',/. J lt*.0. 



Motalia Spaiagiis L ' 102. 



Brissus öcillie Agass -. 104. 



Brissus colund)aris Lamck _ 105. 



1.3. Eciiixrs LACUXOSis L 107. 



Schizaster lacniiosus I; lOx. 



14. Ecinxiis nosACErs L. Pl. U, f. 2 171. 



(ylypeaster rosacfiiis E 172. 



15. lv'llINI'S KE'1'lCUI.ATl'S E 174. 



Clypeastor reticulatiis E.. 175. 



10. EcHiNUS Placknta E. .-- 177. 



Aradinoides Placeiita E 178. 



17. iv'HiNus oRDiciLrs E „ 179. 



A follertivo species 180. 



("dlirllisidll 181. 



