SPATANGID.E. 69 



mouth nearly equal; spines of several forms, 

 moving on rounded knobs, which are perforated. 



C. papillata. Fig. 105 ; n. s. 



Echinus (Linn.). As Cidaris ; but the spines 

 are of one form, and their knobs are not per- 

 forated. 



E. sphsora. Fig. 106 ; % E. lividus. 



miliaris. melo. 



Flemingii. 



* * 

 E. neglectus. E. Norvegicus. 



FAMILY II. CLYPEASTERID^E. 



Echinocyamus (Leske). Body oval, with rounded 

 sides; avenues dorsal, short; vent between the 

 mouth, and the hinder margin. 



E. pusillus. Fig. 107 ; n. s. 



EcMnarachnius (Leske). Body nearly circular, 

 very flat, with the margin nearly sharp and entire ; 

 avenues five, dorsal, short ; vent above, close to the 

 edge. 



E. placenta. Fig. 108 ; %. 



FAMILY III. SPATANGID^. 



Spatangus (Klein) . Body heart-shaped, flattish ; 

 with avenues both above and below; four of the 

 upper ones leaf-shaped; no dorsal impression; 

 impression under the vent transverse. 



S. purpureus. Fig. 109 ; -J-. 





