MARINE ALG OF BEAUFORT, N. C. 555 
PLATE CXII: 1. Halymenia decipiens 1/3 circ. 2. Halymenia floresiaXt/2 circ. 3. Halymenia gelinaria 
X3/5. 4. a, Halymenia gelinariaX 3/7 citc.; b, Halymenia floridanaX 3/7 circ.; c, Amphiroa fragilis- 
simaX3/7 circ. 5. Undetermined species, No. 109/16. 
PuaTe CXIII: 1. Grateloupia filicinaXs5/14 circ. 2. Grateloupia gibbesiiX1/3 circ. 3. Cryptonemia 
crenulataX6/11. 4 and 5. Corallina cubensis. 4. X1/1. 5. XI 1/3. 
Pate CXIV: 1, 2, and 3. Padina vickersie; 1, cross section of thallus and oogonial sorus, oogonia 
almost mature; 2, cross section of thallus and tetrasporangial sorus, showing undivided tetraspo- 
rangia; 3, cross section of thallus and antheridial sorus, antheridia almost mature 272. 4. Nito- 
phyllum medium, type, cross section of thallus showing, below, edge of soral thickening composed 
of three cell layers, three veins shown cut across; the central one has adjoining portion of thallus 
three cells deep with irregular thickenings on walls272. 5. Nitophyllum medium, cross section 
of tetrasporangial sorus, showing soral thickening, undivided tetrasporangia, and veinsX272. 
6. Corallina capillaceaX 50. 
PLatE CXV: 1 to 9. Pheostroma pusillum; 1, margin of thallus, showing separate creeping filaments, 
plurilocular sporangia, hair, etc. X245; 2, enlarged detail, showing immature plurilocularsporangium, 
chromatophores, etc. X 1040; 3, mature plurilocular sporangium in obliquely longitudinal view X 670; 
4, mature plurilocular sporangium viewed from above (end view) <670; 5, margin of thallus (more 
compact than that shown in fig. 1), with unilocular sporangia, a sorus at a and the beginning of a 
sorus at bX245; 6, enlarged detail of thallus, showing chromatophores and unilocular sporangia 
as seen from above X 1040; 7, young unilocular sporangium viewed from above X 1040; 8, the begin- 
ning of a sorus viewed from above X 1040; 9, a mature sorus of unilocular sporangia viewed from 
above X1040. 10to 16. Derbesia turbinata; 10, apex of thallus showing a young lateral branch x 81; 
11, lateral or unequal dichotomous branching X81; 12, dichotomous branching X81; 13 to 16, usual 
forms of sporangia 162, 13 and 15 showing pedicel cells: Drawings by M. A. Howe, from Howe 
and Hoyt, 1916. 
PLate CXVI: 1. Erythrocladia recondita on Dictyota dichotoma, photograph made after staining with 
iodine, showing habit of plant and sporocarps (the larger darker.cells)x<160. 2. Erythrocladia 
vagabunda on Dictyota dichotoma, photograph made after staining with iodine, showing habit of 
plant and sporocarps (some of the larger cells) 160, a small colony of E. recondita with smaller 
darker cells shown near B at the lower right-hand corner. From Howe and Hoyt, 1916. 
PiaTeE CXVII: 1 to 5. Erythrocladia recondita; 1, portion of thallus near margin viewed from above, 
showing outlines of protoplasts and of pyrenoids with outlines of the cortical cells of its host X670; 
2 and 3, portions of cross sections of endophyte and its host, showing the immersed vegetative cells 
and the more or less exserted spermatia (spm.) X670; 4, portion of a cross section showing a carpo- 
gonium with exserted trichogyne X670; 5, portion of pseudoparenchymatous thallus viewed from 
above, showing protoplasts of vegetative cells, spermatia (spm), carpogonium (cpg), and sporocarps 
(spep)X670. 6 to 11. Erythrocladia vagabunda; 6, portion of thallus viewed from above, showing 
outlines of protoplasts and of pyrenoids with outlines of the cortical cells of its host 415; 7, portion 
of thallus showing three vegetative cells, six sporocarps (spep), and five cavities from which carpo- 
spores have been discharged 670; 8 to 9, portions of thalli showing vegetative cells and sporocarps 
(spep) X 415; 10, a single carpospore lying on the surface of its host, in the outer walls of which it is 
already partially immersed X670; 11, a young filament (four-celled stage) viewed from above < 415. 
12 to 17. Microchete nana; 12, a young filament, prostrate, but beginning to tum upward at apex, 
thickness of sheath slightly exaggerated 670; 13, older and normally curved filament showing 
two basal heterocysts (not common), thickness of sheath slightly exaggerated X670; 14, an unusually 
straight, apparently mature filament X245; 15, filament showing curve of a frequent form 245; 
16 and 17, apex and base of filament shown in fig. 15 X670. Drawings by M. A. Howe, from Howe 
and Hoyt, 1916. 
PiateE CXVIII: Acrochetium infestans; 1. Filaments of the usual form in the wall of a hydroid, with 
two exserted filaments, only the protoplasts being shown in the immersed portions, since the cell 
walls are almost invisible 670. 2. An exserted sporangium sessile on an interior filament 670. 
3. An exserted filament of three cells, one being a sporangium and another probably an immature 
sporangium 670. 4. An exterior filament with short branches, short hairs, and a single lateral 
sporangium X670. 5. A single typical cell of an interior filament showing chromatophore, pyre- 
noid, etc. X1o40. 6. Exterior filaments showing sporangia in terminal clusters and a single lateral 
110307°—21———-36 
