( 176 ) 



soon given out in fresh water. Favellse clustered, attached to the 

 pinnae, which are thereby distorted. Tetraspores triparted, spherical, 

 sessile on the upper side of the pinnules. Globose tufts, composed of 

 extremely slender filaments, formed of numerous minute articulations, 

 are not unfrequent, occupying the same position as the tetraspores, and 

 have been considered antheridia (?) or rather viviparous tetraspores. — 

 Phyc. Brit. tab. 231. 



A very common, but by no means equally satisfactory species, many of 

 its supposed forms being so difficult to determine, that we feel very apt 

 to hesitate in their determination. We have never seen the pinnae and 

 pinnules so regular, nor feathered so close to the base as in the pre- 

 sumed normal type, but in general it may be distinguished from G. roseum 

 by its much shorter pinnules and shorter joints, which, at the base of the 

 stem, are nearly free from internal fibres ; to C. Hookeri it is still more 

 closely allied, but the shorter pinnse and pinnules, with the much more 

 distinctly opaque stem of that species, will generally be sufficiently 

 characteristic. 



The present species is both parasitical and rupestral, and seems most 

 partial to the larger littoral fuci, especially F. serratus and vesiadosus, on 

 which it frequently forms dense tiifts or patches of considerable 

 extent. Both kinds of fruit are common, but seldom so plentifully 

 produced on the specimens as they are generally represented in figures 

 and descriptions. 



CALLITHAMNION POLTSPERMUlf . 



EXPLANATION OF DISSECTIONS. 



Fig. 1. — Ramule ■with tetraspores. 

 2. — Tetraspores from same. 

 3. — Pinnse with favellse. 

 4. — Portion of stem. 

 5. — Antheridia ? All magnified. 



