202 INTRODUCTION TO CRYPTOGAMIC BOTANY. 



unknown in the south of England. It descends, however, on 

 the coast of North America, as far as lat 44° 35'. There are 

 several beautiful forms which occur at the Cape, and in 

 other warm seas, which are not found elsewhere ; some of them 

 exhibiting far less conspicuously the cellular reticulation, 

 which is so striking in most of our northern species. Amongst 

 these is Claudea, the most elegant of all Algge, of which 

 specimens occur of extreme beauty, and a fine species has lately 

 been added to this Australian genus. One species of Dasya is 

 very remarkable, as calling to mind the genus Bulbochcde ; 

 and other striking cases of analogy might easily be pointed out. 



Leveillea Schimpen, Den. 



a. TijD of shoot to show the imbrication of the leaflets, the radicles, 

 and circinate tiji. 



b. Single leaflet, with an eroded tip and tuboeform radicle.* 

 e. Tip of entire leaflet. 



d. Stichidium, the tip of which is circinate, and bears imbricated leaf- 

 lets, all magnified. From specimens communicated by M. Lenormand. 



180. The germs Amans^a,^N\ilch. has twoextra-trojoical species, 

 assumes, together with Leveillea and Pohjzonia, the forms of 

 Jungermannioe; and what, is verycurious,iniev6'iZ?ea.the frond 

 is circinate, throwing down roots from the midrib. They are 



* Such radicles occur in Polysiphonia. Voyage axi Pol Sud, tab. 5, 

 fig. 2.^ Nag. Zeitschrift, 1847, tab. 8, fig. 18, 19. 



