744 Scientific Proceedings, Royal Dublin Society. 
problematical bodies consist of two very thin elliptical valves, about 
-015 mm. in length. The valves are saucer-shaped; and one 
which is slightly larger than the other partially includes the 
smaller. ‘The central portion of the outer valve is re-entrant, so 
as to form a short, funnel-shaped collar, connecting it with the 
inner valve. The bottom of this funnel-shaped depression in the 
convex surface of the outer valve is an elliptical plate, which also 
TS 
HANS 
MAO 
SZ Gs 
C f 
(a) Coccolith seen from above, larger valve (dz) Seen from above, smaller valve upper- 
turned upwards. most. 
(4) Viewed obliquely, larger valve upper- (e) Seen obliquely, smaller valve turned 
most. upwards. 
(c) Seen in longitudinal section, smaller (7) Seen in profile, smaller valve above. 
valve above. 
forms the bottom of the smaller saucer-shaped valve. This plate 
is thicker than the rest of the valve, and is perforated. The 
perforation may be single, when it is an elongated oval (the length 
of the oval lying longitudinally in the coccolith}, or it may be 
double when there are two D-shaped holes placed back to back, as 
if the oval perforation had been converted into two by the deposi- 
tion of a bridge of material across its centre. A reference to the 
