INTRODUCTION TO CRYPTOGAMIC BOTANY. 101 



Lammaria unknown to Europe. The truth, however, is that 

 on a considerable extent of the coast, as far as Cape Cod, the 

 species approximate more than our own to Arctic or sub-Arctic 

 forms. Proceeding to the south the Northern Fuci cease, and 

 are gradually replaced by Sargassum. The Callithamnia and 

 Polysiphonice increase in beauty, Delesseria LeprieurU, a 

 New Zealand species, occurs, and the tropical Bostrychice, one 

 of which is found in company with the last-mentioned species, 

 abound in the sestuaries, till, in the Southern states, the forms 

 cease to be those of Western Europe, combining the features 

 of the Mediterranean Algse with those which are perfectly 

 tropical. Species of Gaulerpa abound, and numerous allied 

 genera belonging to Mediterranean or West Indian forms, 

 remarkable for the large quantity of calcareous matter de- 

 posited in their tissues. 



82. A long list of fossil Algse is given by Endhcher, com- 

 piled by Unger from the works of Sternberg, Brongniart, 

 Lindley, and others. Such productions, where the determi- 

 nation necessarily depends on outward form only, and not 

 on intimate structure, are always more or less doubtful. 

 The AlgEe most likely to be preserved in a fossil state are 

 doubtless those calcareous species which resemble corals. 

 None such, however, have at present occurred in any geo- 

 logical formation. The genera enumerated by linger, as far 

 as they resemble in name those proposed for recent Algae by 

 Algologists, will shew the supposed affinity of the fossil 

 species, Gonfervites, Caulerpites, Codites, Unccelites, Hali- 

 serites, Zonarites, Laminarites, Sargassites, Cystoseirites, 

 Halymenites, Sphcerococcites, Chondrites, Rhodomelites, 

 Delesserites* 



83. Amongst the organic remains contained in amber, none 

 seem certainly referrible to this division, though Algoid forms 

 appear, depending on the motion of bubbles of air in a resisting 

 medium, or other physical causes. The tripoli of tertiary form- 



* An actual inspection of specimens arranged in museums, under 

 these and other names, leaves an impression that there is not one of 

 them which is rightly referred to Algfe. Broken specimens of Oldkamia, 

 an undoubted animal, resemble closely some Conferva. Perfect speci- 

 mens, however, at once preclude such au afiinity. 



