252 BRITISH SEA-WEEDS. [Tthoclosjoerme^. 



rain ; it then becomes a lovely crimson. " One of the most 

 charming and symmetrical Algrc in the world, extremely 

 common, and a universal favourite," says Dr. Greville. " A 

 well-known, abundant, and beautiful species, and an especial 

 favourite with amateur weed-collectors, and manufacturers 

 of sea-weed pictures," says Professor Harvey. 



Genus LXXII. DELESSERIA, Lamouroitx. 



Gen. Char. Eroud rosy-red, flat, membranaceous, with a per- 

 cuiTcnt midrib. Fructification of two kinds : 1, capsules con- 

 taining a globular mass of seeds ; 2, ternate granules forming 

 definite sori, iu the frond, or in distinct foliaceous leaflets. — The 

 name is in honom- of a noble French patron of science, the 

 Baron B. Delessert. — Greville. 



1. Delesseria SAN guinea, Lamour. (Plate XIII. fig. 50, 

 plant with leaflets from the midrib.) 



Hab. On rocks and also on other Alga?. We have found 

 it on the roots of Laviinaria digitata. It is biennial. 



The fructification, of two kinds, may be seen on the naked 

 midrib in December and Januarv. The stem is about an 

 inch in length, considerably thicker than a crow-quill. It 

 is occasionally divided into more than a dozen fronds, from 

 two to four inches broad, and from six to ten in length ; 



