206 Rhodora [OcroBER 
NOTES ON TWO RARE ALGZE OF VINEYARD SOUND. 
R. E. SCHUH. 
Tue following notes are offered in a somewhat extended form, in 
the hope that by calling attention to these species their known range 
may be considerably enlarged. 
Giraudia sphacelarioides, Derb. and Sol., has been so confidently 
sought on our coasts that Dr. Farlow, twenty years ago, in the Marine 
Algæ of New England (p. 75), gave a brief description of it. Yet no 
one seems to have discovered it until I found a well-grown, but sterile, 
specimen at Vineyard Haven, in August, 1892. Nothing more was 
seen of it until fruited forms were collected at Cottage City in Janu- 
ary, 1895. It then occurred sparingly on Zostera, intermingled with 
Punctaria, Ectocarpus, and various small species. It is easily over- 
looked, as it is but 5 to 10 mm. high, and usually only a few filaments 
are found together. It may readily be recognized by having a thallus 
which is polysiphonous above and monosiphonous below. A figure, 
copied from Hauck, is to be found in Bennett and Murray’s Cryp- 
togamic Botany, p. 238. As this is a common Mediterranean species, 
it should be sought late in autumn in Long Island Sound and in 
Rhode Island waters. 
Pogotrichum filiforme, Reinke. This small alga was a most sur- 
prising find in our waters. It was before only known to occur rarely 
at Helgoland, where it was collected by Reinbold. It is described 
and figured by Reinke in his Atlas Deutscher Meeres-Algen, p. 62, 
pl. 41, figs. 13-25. In January, 1895, three fertile and unmistakable 
specimens, bearing unilocular sporangia, were found at Cottage City. 
It was then growing on Zostera, in company with Desmotrichum, Girau- 
dia, and various small species. The specimens distributed in Hauck 
& Richter, Phycotheca Universalis, No. 470, are about 40 mm. high ; 
our forms are dwarfed to one tenth that size, but otherwise corre- 
spond closely with the type. The plant consists of several fine fila- 
ments (arising from a thin substratum), which are composed usually 
of a single series of quadrate cells, .o15—.030 mm. wide. Occasion- 
ally these may be divided, so that for a short space two or more series 
may be found side by side. The European specimens are olive- 
brown, but ours are almost hyaline, except for a space along the 
center of the filaments, where the darker spores are borne singly in 
superficial cells which surround the underlying thallus so closely that 
