Howe: PHYCOLOGICAL STUDIES 513 
PLATE 29. Anatheca dichotoma 
A photograph of a portion of the type specimen (La Paz, Vives 7), a little 
more than one third of the natural size 
PLATE 30. Gracilaria Vivesii 
A photograph of a portion of the type specimen (La Paz, Vives 20e), about 
four fifths of the natural size. 
PLATE 31. Fauchea Sefferi 
A photograph of portions of the type specimen (La Paz, Vives 1ze), natural size, 
showing marginal cystocarps, etc. 
PLATE 32. Fauchea (? ) mollis 
A photograph of portions of the type specimen (La Paz, Vives 18a), natural 
size. 
PLATE 33 
1-5. Gracilaria Vivesti 
1. Across section of the thallus of an antheridial plant. 
Surface of antheridial plant. The figure was drawn from a fragment soaked 
ut i ter and mounted in glycerin, in which medium the boundaries of the 
gelatinous walls of the vegetative cells cannot be seen with sufficient distinctness 
to be drawn accurately. In this mature condition of the antheridia, the gelatinous 
outer wall shown in FIG. 3 as covering the antheridium has mostly dissolved away 
and the eo occupy shallow cavities in the co 
rtical section through an antheridium, aie — to arise through 
the ccnceusician of the two outer layers of cortical ce 
4,5. Young antheridia and adjacent vegetative sees in surface view. 
FicurE 1 is enlarged 57 diameters; 2-5, 345 diameters; all from the type speci- 
men ( Vives 20). 
6. Fauchea (?) mollis 
A cross section through the thallus, enlarged 57 diameters. 
7. Cladophora MacDougalii 
apical portion of one filament and a fragment near the apex of another, 
enlarged 11 diameters 
PLATE 34. Halymenia actinophysa 
1. A cross section of the thallus, partially diagrammatic. The figure was 
drawn from dried material soaked out in water and mounted in glycerin, under 
which treatment the outlines of the various structural elements, particularly of the 
large cells of the subcortex, are less distinctly visible than indicated in the figure. 
The larger cells are often so flattened, collapsed, or translucent that the medulla 
commonly appears relatively broader and the cortex thinner than represented; and 
the medulla is often less compact. 
2. 4 — from the cortex and subcortex, showing anastomoses of the sub- 
cortical cells, e 
pean a Aches. showing other forms of cortical cells and their relations 
to pate subcortex. 
