(168) 



brown, without gloss, soon given out in fresh water. Favellse " binate, 

 borne on the pinnse (frequently shortened) of less regular plumules." 

 Tetraspores roundish ovate, tripartite, produced on the upper edges of 

 the tooth-like pinnules, which are placed alternately near the summits 

 of the pinnae. 



One of the largest and coarsest of our British GalUthamnions, as well as 

 one of the most common on the south and south-west of both England 

 and Ireland. It seems, however, to be an ocean sj)ecies, and is rarely, if 

 at all, a native on our eastern shores. 



Its favourite habitat seems to be the perpendicular faces of rocks 

 which are generally left bare at low water, and where it often hangs in 

 large shaggy festoons of several inches in length, and of a peculiar 

 rusty brown colour, more or less deepening into a dark brownish black 

 when moist, but paler and more apparent when dry. 



The species seems to be perennial, and, like all such, exhibits very 

 ditferent aspects at different seasons, and in different situations — at one 

 time presenting little else than naked battered stems, while at another 

 these become covei-ed with long, slender, and delicate plumules of a 

 brighter colour, but the ochry tint is always more or less apparent, and 

 very characteristic of the species. The pinnae are often very imperfectly 

 developed, especially on those sj)ecimens that produce favellee. 



EXPLANATION OF PLATE CXXIIL 



Fig. 1. — CallitJiamnion tetricum, natural size. 

 2. — Pinnule witli tetraspores. 

 3. — A tetraspore from same. 

 4. — Pinnule with favellee. All magnified. 



