192 BRITISH SEA-WEEDS. 



mersed among the surface-cells, scattered. — Gratelotjpia, 

 in honour of Dr. G-rateloup, a French naturalist. 



The majority of the species comprised in this genus 

 grow in warm latitudes, and only one is found as far 

 north as our southern coast. One species, G. Gibbesii, 

 is the largest sea-weed yet discovered in Charleston 

 Harbour, where its fronds attain a length of nearly two 

 feet, and a width of about an inch and a half. The 

 contrast between this plant and our own pigmy G. fill- 

 cina, which is seldom more than three or four inches 

 high and an eighth of an inch broad, is very striking. 



Grateloupia filicina. The fern-like Grateloupia. 



Frond somewhat flattened, twice or thrice pinnate ; pinnae 

 linear, narrow at the base, pointed at the tip, longest at the 

 lower part of the frond, which has in consequence a pyra- 

 midal outline. Spore-nuclei immersed in the branches; 

 tetraspores cruciate, scattered among the surface cells of 

 accessory leaflets. 



The only plant with which this species is likely to be 

 confounded is one of the numerous forms of Gelidium 

 corneum, but the structure of the frond, and the ar- 

 rangement of the spore-nuclei and tetraspores are very 

 different. In the autumn of 1865 I found numerous 

 specimens of this rare plant in both kinds of fruit 

 in shallow rock-pools, near high-water mark, in St. 

 Brelade's Bay, Jersey. " Submarine rocks, about half- 

 tide level, frequently where small streamlets run into 

 the sea," are the usual habitats of this species, which 

 is perennial, and attains its most perfect state in au- 

 tumn and winter. 



