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 (PI. C, fig. i) has an elongated, slender, open habit; the principal 

 branches are not very closely set and are long -and virgate ; the subsidiary branches are small and slender 

 and are rather scatteringly 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) has an 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 apices of the branches are usually straight and tapering, but are sometimes slightly incurved. 

 The third type (PI. CI, fig. i) 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. divaricate 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 i to 6.5 cm. tall, with short, fine branches (PI. CI, fig. 

 2). All such 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 cm. 



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. 



