Plate XVI. 



Alaria tœniafa Ktellm. 



Fijj;. 1. Fiond in iiîitnnil size, with tlie jj-reater part of tlie leuj^tli ot" the 

 ])lfule eiit off. The metasoric s])orophyHs ha^e the soral parts 

 evidently l)roaj:ler than the sterile upper parts. 



Fig". 2. Cross section of the midril) at a point near the a])ex of the l)lade 

 Avhieh measures in diy specimen 3<59 cm. in total leng'th and 

 2 cm. at the broadest part, x 5. 



Fig. '■'). Cross section of the midrib at a p:)int ahout 2~) cm. al)ove the transi- 

 tion point of the same specimen. x 5. 



Fig. 4. Cross section of the midrib of a frond uith dni)licated semi-blades. 

 In the duplicated side of the midrib the spanning cortices are 

 CTU-ved inwards and a tissue similar to tliem is foimd at tlie 

 sinus of the semi-blades. The medulljiry layers of the latter 

 diverge at the outer end of the marginal s^velling of the medulla 

 of the midrib, x 5. 



Fig. ;■). Cross section of the midril) after K.tellman. The tetnigonal form 

 could not be found Mith our specimens. x(>. 



