Nr. 1] SUBAERIAL ALGAE FROM SOUTH AFRICA 35 
1,5—1,8 u, the length 18—21 pu. This form I distinguish as forma 
subtortuosa. 
The other one I distinguish under the name of forma falciformis. 
It is distinguished by having always faleiform cells. Besides, they 
are somewhat more slender than the preceding one, 12—1,5 u 
broad, and 10—15 u long. The cells are never so curved that the 
ends converge, but they are often nearly parallel. 
Observed on a piece of wood, collected near the water-place at 
Saldanha Bay, March 19th. (No. 375). 
It is possible that these two forms, mentioned above, should 
rather be separated as different species; but as long as the true 
nature of ihese organisms is not fully known, I have preferred to 
place them as done above. 
Myxosarcina nov. gen. 
Familiis liberis cubice rotundatis distincte definitis, densis, com- 
pactis, cellulas numerosas aequales, fere cubicas vel polyedricas con- 
finentibus. Divisionibus in tres directiones familiae cellularum 
regulariter dispositarum oriuntur; postea subirregulariter dividi 
possunt, unde familiae aetate magis provectae subirregulares viden- 
tur. Membranae leves, tenuissimae, hyalinae. Familiae tegumento 
mucoso tenui, achroo saepe fere inconspicuo circumdatae. Propa- 
gatio goniditis in gonidangiis cellulis ceteris paullo majoribus ortis. 
Myxosarcina concinna nov. spec. [P1. XVI, Fig. 342—3571. 
Familiis regulariter cubice rotundatis ex cellulis cubicis vel 
polyedricis vilgo 64 regulariter formatis. Membrana cellularum 
tenuissima levi, hyalina, diametro 3—4 u, raro usque ad 5 u ante 
divisionem; contentu cano violaceo. Familiis adultis cellularum 6% 
vulgo 16—20 u, familiis aetate provectis cellularum plurium usque 
ad 32 u diametro. Propagatio gonidiis parvis numerose in gonidan- 
gits a cellulis vegetativis et forma et magnitudine vix diversis ortis. 
Cellulae omnes gonidias formare posse videntur. 
This genus is no doubt most closely related to Pleurocapsa; it 
differs, however, by so important characters, that it forms å genus, 
distinetly separate from Pleurocapsa. 
The genus of Myxosarcina is very characteristic in forming free- 
living colonies, with a definite and distinetly limited circum- 
ference; it is never crusty, as is common in Pleurocapsa. Further 
it differs by having gonidangies of the same shape and size as the 
ordinary vegetative cells. 
The colonies of Myxosarcina are commonly very regularly built. 
The original cell divides in all three directions, whereby arise small 
colonies, consisting of 8 cells. Pl. XIV, fig. 342, 343. By further 
divisions of each of these 8 cells in three directions, arise 64-celled 
eolonies, which much recall the «Sarcina-packages. As'these cell- 
