eupodisce.*:. 



481 



Tribe XXII. Eupodisce/E. 



TABLE OF GENERA. 



Valves with mammi- 

 form elevated ocelli, 

 surrounded by a 

 hyaline zone, whence 



emeige solid 01 

 granular rays, usually 



arranged like 

 feathers ot a quill pen. 



Valves 

 round 



or 

 elliptic. 



f 



I 



Generally 2, rarely 1 or 3 ocelli 

 A single ocellus, eccentric 



Auliscus. 

 Monopsis. 



Valve subquadrangular, 

 an^le 



having an ocellus at each 



Glyphodiscus. 



Valves round or elliptic, cellular or granular, with median hyaline 

 space absent or very small ; striation usually radiant ; two to 

 nine processes surrounded hy a hyaline zone 



o 



,0 

 re 



o 

 a 



to 



> 



Pseudo-auliscus. 



Valves with striation radiant, interrupted at the median por- 

 tion by a linear hyaline space .... Fenestrella. 



3 ! 





> 



o 



.0 



re 



o 



a 



re 



> 



f Valves with 

 connecting 

 project 



costne, moniliform rays or well marked sulci 

 the processes or tubercles, which usually much 



Aulacodiscus. 



f Valves circular or oval, with ocelli placed in com- 

 partments . . . . . 



<D 

 > 

 O 

 JO 

 re 



~ -I 



re 

 > 



Valve with 



cellular 

 structure. 



Craspedoporus. 



' Valves with very fine puncta, indistinctly radiant, 

 showing near the centre a circle of coarser dots 

 and at the margin a corona of dots and a small 



elongated process 



Micropodiscus. 



0) 



> 



o 



.0 



re 



* i 





o 



o 



a 



re 

 > 



Valves circular, with radiating rows of small 



puncta and coarse marginal tubercles . Perithyra. 



Tubercles marginal, rather small, all 

 similar, forming a complete circle ; 

 valves granular, with granules radiating, 

 circular or oval or angular 



o 



a 

 re 



O 



c 





 > 



Cestodiscus. 



I 



o 

 .n 

 re 



o 



c 



> 



I 



Tubercles unequal, 2-3 large, placed 

 at an equal distance between the 

 smaller . . . Isodiscus. 



> 

 o 



.a 

 re 



re 

 > 



Valves with ocelli small, nu- 

 merous, each of them being 

 separated by a small process 

 from the next 



Ocelli, tubercles or pro- 

 cesses usually very 



Rattrayella. 



> 



o 



& 

 re 



if) 



re 



o 



re 

 > 



I 



large, not numerous and 

 usually submarginal ; 

 valve cellular or granu- 

 lar ; granules rarely 

 radiating or small 



Valves with two large 

 elevations, of very slight 

 height .united or covered 

 with radiating puncta ; 

 puncta very fine, ar- 

 ranged in radiating or 

 anastomozing rows 



Eupodiscus. 



Pseudo-cerataulus. 



Ocelli very large or very prominent, few in number and 

 usually submarginal, cells rarely radiating . . Eupodiscus. 



I 



J Ocellus single, submarginal ; valve showing according to 



the focus either hexagonal cells or fine puncta . Roperia. 



Ocelli two, placed on the same side of the valve in a large 

 elongated hyaline depression . . . Bergonia. 



H H 



