PLATE XXXV. 



ECHINOBMSSUS BuODIEI, Wright. 



From the Portland Oolite. 



1 a. EcHiNOBRissus Brodiei, Wright, p. 353. Upper surface, natural size, 

 h. Under surface of the same test, natural size. 



c. Lateral view of the same test, ditto. 



d. Posterior view of the same, showing the short anal valley, and large vent. 



e. Basal tubercles, with hexagonal areolas, highly magnified. 



Pygurus MiCHELiNi, Cottcau. 

 From the Cornhrash. 



2 a. Pygurus Michelini, Cotteau, p. 392. Upper surface, natural size. 



b. Under surface of the same test, showing the vent and its areola, natural size. 



c. Posterior view of the same, showing the relative position of the vent, and border. 



d. Lateral view of the same, showing the excentral position of the apical disc, and the 



shelving character of the posterior half of the upper surface. 



e. Ambulacral area, poriferous zones, and ambulacral plates, magnified twice and a 



half times. 

 /. Apical disc, magnified four times. 



3. Apical disc of the same species, copied from M. Cotteau's work. This figure shows 

 the relative anatomy of the discal elements better than in our best 

 specimen, and exhibits the magnitude of the large madrepbriform body, 

 which covers nearly all the other plates. 



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