К ТЭ ЛИЛЕ RON S TAE КЕТКЕ Т ыы ылы ыла ос тан дама с колосален SSE а а. 
ACROCHAETIUM 85 
appears in our formalin-preserved material to be generally dif- 
fused, except for minute vacuoles, while in the accompanying 
Acrochaetium clandestinum the chromatophores have more or less 
definite forms as described and figured under that species. We 
find no trace of a pyrenoid in the vegetative cells, but in the spores 
there is a denser central body that sometimes shows a starch 
reaction with iodine. 
Acrochaetium catenulatum is evidently related to the West 
Indian Chantransia crassipes Bórg. (Bot. Tidssk. 30: І. Ў. г. 1909) 
and the Danish Chantransia moniliformis Rosenv. (Kgl. Danske 
Vidensk. Selsk. Skrift. УП. 7: 99. f. 28, 20. 1909). Its affinity 
with C. crassipes is perhaps particularly close, but it appears to 
differ in being a larger plant, in having cells 7-11 и broad instead 
of 4—7 и, in having а basal cell that in the mature condition of the 
plant is not especially different from the other cells of the main axis 
and is often a little smaller than they rather than larger, in the 
absence of hairs, in the conspicuous hamate curving of the main 
axis of the larger fertile plants, in the terminal as well as lateral 
sporangia, in the occasional simultaneous formation of sporangia 
by two or three concatenate cells, etc. Тһе basal cell, it may be 
remarked, is, in most cases, partially immersed in the wall of its 
host. It is at first larger and more refringent as to its contents 
than the other cells of the young filament, but eventually is 
scarcely different from the adjacent cells. 
From Chantransia moniliformis Rosenv., the Peruvian plant 
differs in having one recognizable erect main axis instead of two or 
more, in the relatively shorter cells of the adult condition, in the 
absence of hairs, in the smaller, terminal as well as lateral, and 
occasionally concatenate sporangia, in the apparently different 
chromatophore, etc. Many young plants of Acrochaetium catenu- 
latum have been examined without finding any trace of hairs. 
Те apices, however, as shown in some of our figures, often bear 
the remains of the walls of evacuated sporangia. 
PLATE 31, FIGURES 12-18. Acrochaetium catenulatum 
12. А “м plant, showing mode of branching, form of the cells and chromatophores, 
ne emptied and three filled monosporangia, etc. 
13. А portion of another plant, ник three two-celled lateral branches in each of 
erminal ce mes a monosporangium and in two of which 
the other cell also к а monosporangium simultaneously. 
