THE YAN YEAN RESERVOIR, VICTORIA. 81 
a condition corresponding to that which obtains in (ronyaulax may easily 
have been produced. Itis therefore quite possible that the genus Gonyautlax*, 
Fig. 10. 
=, 
EJ 
Ed 
22) 
| 
Ss то, / 
ca m - ( 
Ao moram. Qmm 
Е = я S 
ә Pret D \ y 
Е: у 
; - 
QE omy 
A 
E F K 
A-G. Peridinium Роза, Lemm., var. australe, var. п. A, ventral view; B, dorsal 
view; C, epivalve; D, hypovalve. Е, outline of epivalve with the various 
plates named :—1-7, præ-equatorial plates; ad. 1 and ad. 2, dorsal apical 
plates; ар. l-av. 4, ventral apical plates; r, rhomboidal plate. Е, outline of 
hypovalve to show plates:—1-5, post-equatorial plates; ant. 1 and ant. 2, 
obliquely disposed antapieal plates, A-F, x 500. G, single plate to show 
areolations, x 1000. 
Н-Ј. Peridinium inconspicuum, Lemm., x 1000. Ј, old cell-wall containing а cyst. 
К. Dinobryon elegantissimum, sp. n., x500. 
the species of which are neither so numerous nor so widely distributed as 
those of Peridinium, has had a direct origin from the latter genus. 
67. PERIDINIUM 1NCONSPICUUM, Lemm. in Abh. Nat. Ver. Bremen, xvi. 
(1902) p. 350; in Engler, Bot. Jahrb. xxxiv. (1905) t. 8. fig. 1. 
Long. 17-18 ш; lat. 13:5-15 ш; diam. cyst. 18°5-15°5 р. (Техі- 
fio. 10, H-J.) 
Hab. Yan Yean Reservoir, at the weedy margins (Nov. 1905-Jan. 1906). 
This minute species was very abundant in December 1905, in which month 
a few resting cysts were formed. These were ovoid-globose, with smooth walls, 
and a little smaller than the somewhat distended wall of the mother-cell. 
* The genus Gonyaulax has been recently revised by Lemmermann in Botan. Centralbl, 
xxi. (1907) pp. 296-300. 
LINN, JOURN.—BOTANY, VOL, XXXIX. G 
