5*8 



P.RUNIA. 



rising in order to bend back at a right angle, thus forming a rather elevated 

 wall or prominent margin, which is reflected in the same direction as the 

 superior portion, but inclining more or less outwards, to form a gently convex 

 edge of variable size. 



The general form of the valve is very similar to that of a plate whose 

 rather deep side is at a right angle with the bottom. 



On the margin and at its intersection with the wall is found a row of 

 coarse oblong cells with a rounded outline placed end to end, and forming a 

 broken but uninterrupted line, giving the appearance of a festoon surrounding 

 the base of the wall. This corona of coarse cells is lodged in a channel 

 formed of two silicious plates ; one of these being a continuation of the valve, 

 and the other, exterior, which is extremely thin, follows the undulations, which 

 form the cells, and is very finely punctate. 



This arrangement of the coarse cells is more evident in fragments inclined 

 in the same direction as the margin on which they are placed. Dimensions 

 of one arch of the corona "003 mm. 



Between each cell is found a cavity or depression of the valve; this regular 

 depression produces an undulated plait which surrounds the corona of cells. 



Superior surface of the valve : Diameter '310 mm., with radiant and 

 punctate striation, 5 to 6 striae as a mean in 'oi m., and formed of small 

 beads increasing in size as they approach the centre. No distinct area. Rays 

 ending between each pair of coarse cells. 



The punctate lines and the rays continue the whole length of the wall as 

 far as the cells ; outside that, only the punctate lines are continued, and the 

 puncta are more accentuated. 



The silica of the cells is very robust, while that of the rest of the valve is 

 very thin and flexible, resulting in only fragments of this species being found. 

 Its colour is drab yellow. 



Habitat Limestone from Japan. 



Mr. Tempere describes two species in this genus, B. Japonica Temp., 

 figured in the text (fig. 271), taken from a photograph which Mr. Tempere has 

 been good enough to send me, and Brunia mirabilis Temp., also coming from 

 Japan, and which differs from the first by the absence of rays. I have in my 

 possession a specimen of this form from Sta. Monica, where it was found in 

 1878, by Mr. Weissflog. 



