486 BULLETIN OF THE BUREAU OF FISHERIES. 
River, and in Core Sound at Davis Island and Lennoxville. Very abundant at Ocracoke, N. C., on rocks, 
shells, and Zostera from low water to 60 cm. below low water. Abundant in sound near inlet, Wrights- 
ville Beach, N. C., on shells 15 to 45 cm. below low water. Few plants about 2 cm. tall.in sound near 
inlet, Pawleys Island, near Georgetown, S. C. 
The species varies greatly in appearance. Three types connected by numerous intermediate forms 
may be distinguished. The first (Pl. C, fig. 1) has an elongated, slender, open habit; the principal 
branchesare not very closely set and are long and virgate; the subsidiary branches are small and slender 
and are ratherscatteringly arranged on the main axis and the principal branches; the ultimate branchlets 
are numerous on the main axis and the branches, being short, slender, simple, spinelike processes from 
a narrow base; the apices of the main branches and of some of the subsidiary branches are often incurved 
and thickened to form tendrils. The second type (PI. C, fig. 2) hasan elongated, more or less slender 
habit, varying from rather open to rather dense; the principal branches are more or less closely set, 
more or less elongated, and more or less virgate; the subsidiary branches are more richly branched, 
and more closely set on the main axis and principal branches than in the first type, and are often 
larger; the ultimate branchlets more or less densely clothe the main axis and the branches, being 
shorter or longer, slender or coarser, simple or branched, spinelike processes from a narrow or wider 
base; the apicesof the branches are usually straight and tapering, but are sometimes slightly incurved. 
The third type (Pl. CI, fig. 1) has a shorter, rigid, dense habit; the principal branches are closely set, 
short or slightly elongated, and divaricate; the subsidiary branches are short and coarse and are closely 
set on the main axis and the principal branches; the ultimate branchlets densely clothe the main axis 
and the principal branches, being short, coarse, branched, staghornlike processes from a broad base; 
the apices of the branches are straight and taper only at the very ends. 
These types are not sharply defined, and different branches of the same frond may show the char- 
acters of two or even of all three types. The statements of previous authors that tetrasporic and cysto- 
carpic plants show constant differences in habit do not hold strictly in the present case. Although the 
majority of plants of the first type are tetrasporic, and, so far as observed, all the plants of the third 
type are cystocarpic, the first type includes cystocarpic plants also, and the second type includes both 
tetrasporic and cystocarpic plants. In many cases the tetrasporic and cystocarpic plants are indis- 
tinguishable in appearance. 
Although some of the Beaufort plants have characters that are given for H. armata (Mert.) J. Ag. 
and H. divaricata Grev., others closely resemble the type of H. musciformis and other authentic speci- 
mens of this species and are so connected with the extreme variants by intermediate forms that it seems 
impossible to place the specimens in more than one species. 
Of the plants observed from July to October, about 80 per cent were tetrasporic and 20 per cent 
cystocarpic. Only one antheridial plant has been found. In unfavorable situations and in spring 
(April 21, 1908) all the fruiting plants observed were tetrasporic. The species winters in this region 
by means of small, matted, slender specimens 1 to 6.5 cm. tall, with short, fine branches (Pl. CI, fig. 
2). Allsuch specimens observed, with the exception of some collected April, 1908, were sterile. During 
the season 1908-9 all specimens observed as late as October 17 had their usual summer size and appear- 
ance; those collected November 18 were all in the winter condition as described above; this condition 
was maintained through the collection of April 15; but on May 14 the species was abundant, with all 
the plants in the summer condition, many being as tall as 22 em. 
The incurved tips function in a way similar to the tendrils of flowering plants, clasping any small 
support which they may find, firmly attaching themselves by outgrowths from the surface of contact, 
and sometimes penetrating within the supporting body. In one case a plant of this species was observed 
with its tendrils so closely wrapped about a stem of Leptogorgia virgulata that they had formed con- 
strictions in the hydroid, the ends of many tendrils were embedded in the Leptogorgia, and some of 
them bore branches within its body. Since this Leptogorgia does not continue to increase in diameter, 
it would seem that this was due to the active constriction and penetration of the algal tendrils. The 
rapidity with which this alga may make active attachments is indicated by the fact that when plants 
were placed in a jar of sea water with oyster shells they had attached themselves to the shells within 
24 hours by the tips of several branches. Similar cases have been observed under natural conditions, 
some branches bending over and attaching themselves by their tips to the substratum. 
