34 INTRODUCTION. 



lateral tubercle containing spores ; fig. 2, a branchlet with 

 sticMclia containing tetraspores : all magnified. 



At E, are figures of two kinds of fructification observed 

 in abundance on Odonthalia dentatam QOixXj winter. Fig. 1, 

 capsular fruit ; and fig. 2, stlchidia. 



On flat membranaceous Algae^ two kinds of fructification 

 are common. At letter F, fig. 1 represents a portion of the 

 frond of Rhodomenia bifida , with imbedded tubercles, called 

 also coccidia. These contain spores or seeds : magnified. 

 Fig. 2 represents a portion of the frond of Nltophijllum 

 punctatuMj or rather^ it is one of the 8ori with wliich the 

 frond is spotted. These sori consist of an assemblage of 

 tetraspores : magnified. 



The genus Callithamnion has two kinds of fructification. 

 At the letter G, fig. 1 represents the capsidar fruit of a 

 Callith amnion, sessile on the upper side of the pinna. 

 Fig. 2, a branchlet with a bilobed favella. The favellse 

 have sometimes only one lobe. 



There is another kind of fructification, called by Agardli 

 nemathecia. These nemathecia, or warts, are concealed 

 under leafy processes ; and at letter //, fig. \, is a wart 

 on Flnjllopliora rubens, with one of the leaves removed 

 to show the nemathecia. Fig. 2 represents the moni- 



