PLATE IIL 



PRASOrOIlA OCULATA. (PugO. 11) 



Mgme I. Fragment of the zoariuni showing tlic characteristic surface orna- 



mentation. Natural size. 



" J a. Side view of the same, showing the thickness of the zoarium. 



" 1 h. Under surface of a young indivi(hial, attached to a dorsal valve of 



Ortliis iestvdinariaf shewing the wrinkled epitheca. Natural 



size. 



" 1 c. Upper surface of the same. 

 " 1 (1, Side view of the same. 



" ] €, Tangential section showing the two sets of tubes with a cluster of 

 the smaller ones. Enlarged about fifteen times. 



" 1 f. Portion of the same section enlarged about ninety times. 



" I g. Longitudinal section, enlarged about thirty timos. 



PRASOPORA AFFINIS. (PagC 12.) 



Figure 2. l^^ragment of the zoarium. Natural size. 



" 2 a. Side view of the same. 



^' 2 h. Tangential section, enlarged about thirty tiinos. 



" 2 c. Longitudinal section showing the whole thickness of the zoarium. 

 Enlarged about thh-ty times. 



