NELLIE CARTER: FRESHWATER ALGE. 63 
exactly with Z. rhynchonema Hansg., differing only in the scrobiculate middle 
wall of its zygote. In this latter character it is nearer to Z. pectinatum, and 
for this reason has been referred to the variety decussatum of that species, 
which it resembles very much in its slender filaments and longer cells. The 
zygospores, however, were usually formed in the conjugation tube by lateral 
conjugation instead of by scalariform conjugation, as is usual in that species. 
The latter form of conjugation occurred very occasionally, and only as a 
great exception. Lateral conjugation in typical Z. pectinatum has, however, 
already been reported by Fritsch & Stephens in Trans. Roy. Soc. South 
Africa, vol. ix. 1921, p. 53, fig. 24. 
Sterile species of Zygnema occurred in Nos. 338, 384, 1356, 1986. 
SPIROGYRA COMMUNIS (Hass.) Wittr. Mont Canala ; in sluggish stream. 
1242. . 
Sterile species of Spirogyra occurred in Nos. 176, 384, 528, 852 (with 
unripe zygospores), 1242, 1356, 1359. 
DESMIDIACEZÆ. 
GONATOZYGON MONOTÆNIUM De Bary. Canala; in washings of Azolla from 
slowly running water in diteh. 1359. Europe, America, India, Malaya. 
Var. PILOSELLUM Nordst. Canala ; in fairly swift stream amongst Spirogyra 
sp. 1356. Ireland, Brazil, 
G. KixAHANI (Archer) Rabenh. Rivière du Carénage ; amongst alge 
attached to rocks. 384. Europe, America, Malaya. Forma major, pyre- 
noidibus numerosissimis. Long. cell. 660 a ; lat. 18u. Riviere du Carénage. 
384. 
Cyrinprocysris Bresissonit Menegh. Plaine des Lacs; in shallow rain 
pools. 338. Rivière du Carénage. 384. Europe, India, Malaya, Australia, 
New Zealand, E. Africa, America. 
Nerrium Drarrus (Ehrenb.) [tzigs. & Rothe. Plaine des Lacs. 338. 
Europe, China and Japan, India, Malaya, Australia, New Zealand, America. 
Var. constrictum W. & G. S. West. Rivière du Carénage. 384. Europe. 
PENIUM MARGARITACEUM (Ehrenb.) Bréb. Ouendjam Forest ; in slowly 
running stream. 1986. Europe, Java, New Zealand, E. Africa, America. 
The specimens were much more rounded at the extremities than usual, and 
were provided with a large, conspicuous terminal vacuole at each end. 
P. mixuTIsSIMUM Nordst. (Pl. 4. fig. 15.) Plaine des Lacs. 338. 
Europe, Burma, Siam, Madagascar, 8. America, The specimens were 
slightly longer and narrower. Long. 17 u; lat. 84. Aygospores were not 
uncommon. 
