BY G. I. PLAYFAIR. 



801 



Text.fig.5. 

 a-/, Peridinium caudatum vax.guildfordense., n. var. (x 1000). 



(a) dorsal view, (b) ventral view, (c) epivalve, (d) hypovalve, 



(e) more oval form, (f) hypovalve of same. 

 g, Peridinium caudatum mini, forma (x 1000). 



culty discernible; intercalated plates, as is usually the case here 

 even in the largest species, being generally absent. The two 

 antapical plates of the hypovalve are not quite equal, and are 

 arranged obliquely . In the epivalve the rhomboidal plate is con- 

 tinued right into the subapical pit . 



Var. plaxktonicum mihi. (Text-figs. 6, 7). 



Forma late ovata, modo angulata; fossa transversa circulata. 

 Epivalva conica, lateribus symmetrieis, fovea apicali instructa. 

 Hypovalva tarn lata quam epivalva, a tergo modo excavata; 

 fossa longitudinali valde dilatata usque ad marginem posteriorem 

 extensa; tabulis antapicalibus modo inaequalibus, paullo oblique 

 dispositis. 



Long. 23-32, lat . 20-28 ^ Sydney Water Supply (66, 115) ; 

 Brisbane. 



