Marine Plants of Nha Trang — Dawson 
19. Plants consisting of coenocytic filaments 
penetrating coral and shell. Ostreobium 
Plants free, not as above 20 
20. Thallus spongy, composed of interlaced 
filaments forming a surface layer of 
swollen utricles . Codium 
Thallus not spongy, not as above ... 2 1 
21. Coenocytic thallus consisting of + — 
coarse, basal, cylindrical, rhizoid-bearing 
parts and erect, specialized assimilatory 
branches . Caulerpa 
Coenocytic thallus consisting of several 
erect axes bearing pinnate or multifarious 
branches 22 
22. Erect axes bearing pinnate branchlets 
without basal septa Bryopsis 
Erect axes bearing multifarious branch- 
lets, mostly with basal septa 
Pseudobryopsis 
23. Filaments prostrate, spreading; plants 
epiphytic or endophytic .... Entocladia 
Not as above 24 
24. Filaments bearing septa at base of branch- 
es 2 5 
Filaments mostly without septa at base 
of branches Cladophoropsis 
25. Thalli erect, free 26 
Thalli congested and anastomosed into 
a loose, spongy mass Boodlea 
26. Thalli rarely branched, 15-19 m in di- 
ameter Rhizoclonium 
Thalli H abundantly branched, mostly 
over 20 ^ in diameter 27 
27. Branches all free Cladophora 
Branches partially united laterally to form 
a reticulum of flabellate form . . . Struvea 
383 
Fig. 4. Ulva lactuca: Habit, X 1. 
Ulva lactuca Linnaeus 1753: 1163 (England); 
Tseng 1935: 101; Smith 1944: 45, pi. 3, 
figs. 6 , 7 pjg 4 
LOCAL DISTRIBUTION: Abundant on inter- 
tidal rocks adjoining the village of Truong 
T% (11294). 
Key to the Species of Enteromorpha 
1. Thalli simple, essentially unbranched . . 2 
Thalli branched 3 
2. Thalli inflated, H constricted and con- 
torted E. intestinalis 
Thalli smooth, slender E. tubulosa 
3. Branched near the base, the branches 
simple, but not uniseriate and capillary 
E. kylinii 
Branched throughout, with many uni- 
seriate, capillary ultimate branchlets .... 
E. clathrata 
Enteromorpha intestinalis (L.) Link 1820: 
5. Ulva intestinalis Linnaeus 1755: 418 
(Sweden). 
LOCAL DISTRIBUTION: Abundant on rocks, 
Sta. 6 (11226); Sta. 10 (11334). 
