PLATE XXXII. 



Clypeus Agassizii, Wricjht. 

 From the Inferior Oolite. 



1 n. Clypeus Agassizii, Wright, p. 378. Lateral view, natural size. 



b. Posterior view, showing the shallow anal valley, and superficial oblong vent. 



c. Ambulacral area, poriferous zones, and inter-anibulacral plates, magnified twice and a 



half times. 



d. Portion of the basal ambulacral area near the mouth, showing the arrangement of 



the pores in triple obhque ranks, magnified four times. 



e. Tubercles from the base, with miliary granules around them, n)agnified. 



/. Tubercles from the upper surface, showing the regular disposition of the granules 

 ■ around the areolas, and on the intermediate surface. 



