128 COLLINS AND HERVEY. 



from the segments next below. Antheridia developed from leaves, 

 conical-ovoid. Color rosy red; substance soft. 



From the few 4-tubed species of Lophosiphonia this is distinguished 

 by branching characters, but specially by the great development of 

 the rhizoids, which show a remarkable adaptation to its habitat, the 

 fronds of C odium. The rhizoids take the shape of utricles, of much the 

 same shape and size as those of the host, but in reversed position. At 

 first a relatively slender cell, cyclindrical, or occasionally flattened in 

 a line with the axis of the filament, as soon as the rhizoid has pene- 

 trated between the stouter parts of the Codiwn utricles it expands, 

 and wedges itself in tightly among the latter. As seen under the 

 microscope, there is a striking contrast between the rosy color of one 

 set of utricles, and the green of the other. Type in Collins herbarium, 

 No. 7456, Gibbet Island, March, 1913, Hervey; also from Gibbet 

 Island, Jan., Smith's Bay, March, Hervey; Tucker's Town, April, 

 Cave near Ducking Stool, Hungry Bay, May, Collins. 



3. L. OBSCURA (Ag.) Falkenberg, 1901, p. 500; P. B.-A., No. 1892; 

 Hutchinsia obscura Agardh, 1828, p. 108; Polysiphonia obscura 

 Harvey, 1846-51, PI. CII. A. Moseley, as Polysiphonia exilis; 

 Smith's Bay, Spanish Rock, Jan., Gibbet Island, March, Harrington 

 Sound, Dec., Hervey; North and South Shores, April, May, July, 

 Aug., Collins. Common everywhere on rocks between tide marks, 

 and in caves, where in well sheltered places it reaches even above 

 ordinary tides. It varies considerably in size and in luxuriance of 

 branching, but is not likely to be mistaken for any other species. 

 Young plants bear long hairs (leaves) in dense branching tufts. 



BOSTRYCHIA Montagne. 



1. Main axis ecorticate. 1. B. rivularis. 



1. Main axis corticate. 2. 



2. Long monosiphonous ramuli present. 2. B. tenella. 



2. -Only a few terminal segments monosiphonous. 3. 



3. Tips of branches incurved; rather coarse. 4. B. Montagnei. 



3. Branches straight; slender. 3. B. sertularia. 



1. B. RIVULARIS Harvey, 1853, p. 57, PL XIV. D. Walsingham, 

 April, Hervey. This species, the only one occurring as far north as 

 New England, has been found only once in Bermuda, and then in a 

 quite small form, not over 2 cm. high. It was sparingly scattered 

 among B. Montagnei. 



