816 



PERIDINEAE Of XEW SOUTH WALES, 



P. australe. On all the other plates of the cell there are 2 rough 

 incrassate parallel ridges transversely disposed. 



PERIDINIUM HIEROGLYPHIC!!!! mihi. 



Syn. Peridinium tabulatum var. hieroglyphicum Plavf., I.e., 

 p. 543, PL lv., f. 13. Long. = lat. = 54 ^ 



Var. ovatum, n. var. (PI. xliii., f. 4, 5). 



Forma ovata, plus minusve angulata; fossa transversa spirali 

 in partes duas insequales divisa; superne et a tergo spinis 

 minutis hinis saape ornata; zonis interealaribus nullis. Mem- 

 brana notis hieroglyphicis disjunctis ornata . 



Long. 44-46 J, lat. 40-42, epiv. alt. 27£ p. Sydnev Watei 

 Supply (100). 



Var. rotundum, n. var. (PI. xliii., f. 6). 



Forma late-ovalis, ubique rotundata; fossa transversa spirali 

 in partes duas inasquales vel ajquales divisa; interdum sine 

 spinis . 



Long. 46J-48J, lat. 42-44*,*. 



Sydney Water Supply (100) . 



This is a very rare species, and I have not been successful in 

 obtaining end views of the hypovalve and epivalve in any of its 

 forms. In dorsal view all that can be seen are four plates in 

 each half, a large central almost rectangular plate with part' of 

 one on each side, above and below. In ventral view the mark- 

 ings are normal, with a well-defined longitudinal furrow hardly 

 dilated behind but running right back to the posterior margin; 

 in the epivalve the rhomboidal plate extends quite up to the 

 apex. In all forms tbe membrane is covered with irregular in- 

 crassate markings. 



*s- 



Genus Ceratium Schrank . 

 Ceratium hirundixella O. F. Muller. 



Long. 244-324, lat. 50-63, corn. apic. 113-144 ^ 



Sydney Water Supply; Auburn. 



Our specimens agree very well with the excellent figure given 

 by Schilling, op. cit., fig. 62, but the apical horn is perfectly 

 straight and the antapical horns not quite so sharp-pointed. I 

 have not yet observed any of the depressed forms commonly 

 noted in European waters. 



