OF THE THIRD TANGANYIKA EXPEDITION, 197 
duplo longioribus, polis subrotundatis ; cytoplasmate late wruginoso et 
granuloso (fere ut in Chroococco turgido). 
Long. cell. 5:5—10 ш; lat. cell. 4:5-55 ш: crass. vag. 11—15 
ad 27 y). 
Tanganyika.—Epiphytie оп Chetomorpha Linum, floating in Kituta Bay 
(26 Aug. 1904 ; no. 79). 
This plant belongs unquestionably to the Chroococcacez, the cells having 
very much the same structure as those of Chroococcus. It would fall naturally 
into Hansgirg’s genus Chroodactylon (Ber. Deutsch. Bot. Ges. 1. (1885) t. 3), 
but for the fact that Hansgirg has since placed both Asterocystis, Gobi (1879), 
and his own genus ( ‘hroodactylon (1885) as sections of © Allogonium, Kütz." 
(vide Hedwigia (1887), Heft 1) Although Hansgirg was in error in 
reviving “ Allogonium," a name given by Kützing to a number of Algz of 
widely different affinities and all of which are now placed in other genera, 
yet he was evidently of the opinion that Asterocystis and ( hroodactylon were 
scarcely distinct. It is for this reason that I have placed the African plant 
as а species of the former genus. Schmitz (in Engl. Natür. Pflanzenfam. 
1 Teil, Abt. 2, p. 314) places Asterocystis in the Bangiacew. but the species 
observed from Tanganyika is a typical Blne-green Alga. 
The colonies of Asteracystis africana reach a diameter across the spreading 
branches of about 360 и. The gelatinous sheath at the base of the primary 
filament is somewhat expanded and is firmly attached to the wall of the 
Chatomorpha, in which it makes a pit-like depression often 14 w in depth. 
№ (usque 
МАУТСОГАСЕЖ. 
319. NAVICULA SERIANS, Bréb. in Кі. Bacill. (1844) p. 92, t. 30. fip. 23; 
W. Sm. Brit. Diat. t. 16. fig. 130. 
Nyasa.—In scrapings from bottom of ss. *Guendolen’ at S. end of lake 
(15 June, 1904; no. 577). 
СОМРНОМЕМАСЕЖ. 
380. RHOICOSPHENIA CURVATA, (Aütz.) Grun. т Abh. zool.-bot. Ges. Wien, 
x. (1860) p. 511; Van Heurck, Synops. Diat. Belg. t. 26. figs. 1, 2, 3. 
Tanganyika.—On the bottom of Dr. Cunnington’s dau (24 Jan, 1905 ; 
no. 217). 
The University, Birmingham, 
19th March, 1907. 
LINN. JOURN.—BOTANY, VOL. XXXVIII. 
