ro2 



CLADOGRAMMA. 



GENUS 163. CLADOGRAMMA EHR., 1844. 



Valve discoid, with margins and 

 centre raised, hyaline or punctate, 

 centre sometimes stellate, rays 

 linear, more or less bifurcated, and 

 somewhat irregular ; interspaces 

 hyaline, or with curved or sinuous 

 lines. 



Fig. 246. 

 Cladogramma Cebuense. 



This genus includes four species, three of which are fossil and all four 

 circular. I give above (fig. 246), CL Cebuense Grun., which is found in the 

 island of Cebu (Phillippine Islands). 



GENUS 164. MASTOGONIA EHR., 1844. 



Fig. 247. Mastogonia Crux. 



Valves hyaline, divided by 

 simple rays, centre very small, 

 almost obsolete, hyaline or 

 granular. Valves convex, 

 without spines. Frustules 

 solitary. 



This genus is approximate to Stephanogonia which we have placed, in 

 consequence of its spines, with the Melosirece. I give (fig. 247), Mastogonia 

 Crux Ehr., from the Bermuda Archipelego and a specimen of which from 

 Richmond (Virginia), I have in my possession, 



