66 AKT. 12. — K. YENDO. 



und finally filiform; at first patent, but soon bent upward. They 

 usually divide into a few segments, and those at the apical 

 regions are mostly simple. Very often we find a simple leaf 

 attaining 20 cm. in length. 



The basal leaves — the young branches — as well as the leaves 

 on the elongated stems are always flat on the same plane in which 

 the flattened stem lies. This character distinguishes the plant 

 readily from the other members of the Bactrophycus or Eusar- 

 gassum. An elevated rib runs along the median of the leaf, 

 sending out lateral costœ into the lobes if any. In the upper 

 filiform leaves these costœ are not evident, especially in the dried 

 material ; but the cross section of leaves of this sort from a fresh 

 specimen is elliptical, with the middle portion slightly elevated 

 on both surfaces. Cryptostomata are always present along the 

 edges of tlie upper leaves and stems. In the lower leaves, how- 

 ever, they are, as a rule, obscure. 



Ramules are axillary. In the beginning they appear as short 

 subcompressed processes starting from the upper margin of the 

 petiole. Eacli process develops into a vesicle and a ramule 

 starts from the basal point of the vesicular stalk. (Plate VIII. 

 fig. 3, 5). 



Vesicles are obovate or subspherical, with a complanat- 

 ed stalk nearly as long as the vesicle, and each crowned 

 with a simple or pinnately divided filiform leaflet. In the 

 upper vesicles several cryptostomata are found as elevated brown 

 spots. 



Receptacles are linear, simple or often divided, round at the 

 apices, attenuated below,, disposed on a short ramule in a disti- 

 chously pinnate manner. Cryptostomata are also found on the 

 receptacles, 



