Tribe XXIII Heliopelte/E. 



TABLE OF GENERA. 



Valves with triangular or cuneate compartments, equal, alternately- 

 depressed and elevated, usually two layers, one reticulate, the other 

 punctate 



f Valve very finely punctate, over the whole surface, elevated portions 

 ending in an edge, giving the appearance of spokes of a wheel, 

 each terminated by a large ocellus 



c 

 o 



o 



G 



V 



Si 



5 > 



c 

 o 



c 

 o 



o 



c. 



-a 



3 



o 

 c 



D 



Actinoptychus. 



Actinodiscus. 



<L> 

 > 



O 



.O 



1) 



> 



f Umbilical area covered with scattered coarse blurs. Valve 

 with coarse puncta divided into cuneate compartments by 

 the interposition of elevated plicae . . Truania. 



f Valve with numerous marginal compartments, separated 

 by septiform depressions ; umbilicus rounded, 

 hyaline. Intermediate portion finely punctate, 

 puncta radiating, interrupted at certain distances by 

 blank spaces .... Anthodiscus. 



f Valve with unequal compartments ; elevated com- 

 partments very narrow, ending in a process ; 

 depressed compartments broad, reticulated, 

 triangular, interrupted at the base by a short 

 elevation, elongated into the umbilical hyaline 

 portion ..... Actinodyction. 



f Margin showing numerous elevations (they 

 themselves being subdivided) and separa- 

 ted by deep sulci ; sulci in the form of 

 scales at the edge of the margin and 



extending towards the interior as far as 

 the umbilicus 



I 



v 

 > 



o 



.a 



- 1 



o 



c 



> 



> 

 o 

 a 



I 



Lepidodiscus. 



o 



G 



I 



I 



Valve similar to the preceding, from which 

 it differs by the whole median portion 

 being occupied by strias, radiant, flame- 

 iike,' very finely punctate, and by the 

 finely granular umbilicus, surrounded by 

 a hyaline circle 



Wittia. 



GENUS 157. ACTINOPTYCHUS EHR, 1838, Char, emend. 



Fig. 232. Actinoptychus undulatus , 



