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PACIFIC SCIENCE, Vol. VIII, October, 1954 
Fig. 2, a-f, Diplanthera unmervh: a. Habit of a portion of a plant showing rhizome, roots, and erect shoot, 
X 2; Z', a leaf tip, X 6; c, a portion of a plant bearing a male flower, X 5; <3^, a portion of a plant bearing a female 
flower; e, a young fruit, X 5;/, transection of a leaf, X 15. g, Thalassia hemprichti: An erect shoot and part of a 
prostrate stem, X 1. 
Individual filaments tapered from base to 
apex 5 
4. Trichomes 9-12 jd in diameter 
Hormothamnion solutum 
Trichomes 6-7 m in diameter 
. Hormothamnion enteromorphoides 
5. Filaments densely packed together, form- 
ing an expanded, crustaceous, or plicate 
Plants multicellular, filamentous, the fil- 
aments free or loosely to densely packed 
together 2 
2. Individual filaments of a simple row of 
uniform cells; heterocysts absent 9 
Heterocysts present 3 
3. Individual filaments of a simple row of 
uniform cells 4 
