lüO AKT. 12. K. YENDÜ. 



minutely serrated at the 'upj)er margin, or often entire. Tliey 

 are usually destitute of cryptostomata, and are frequently sym- 

 metrical. Those on the upper portions of the principal stems, as 

 well as those on the lateral branches, are without exception asym- 

 metrical and situated perpendicularly. They are obliquely cuneate 

 in general outline, attenuated below and ending in a filiform petiole. 

 The upper margin is entire and recurved upward, the lower is 

 minutely or coarsely dentated, not infrequently subentire. The 

 total length of the leaves varies to a considerable degree even 

 in the same individual, i-anging from -|cm. to 3 or more cm. 

 When the plant has attained maturity the fulcrant leaves on 

 the principal members have mostly dropped off, and the lateral 

 branches j^lay the important part of the frond. The leaves on 

 the terminal ramulets are usually narrowly cuneate, entire, or 

 shallowly bi-trifid at the apices. 



The lateral branches are axillar}^ As the fulcrant leaves 

 are per2)endicularly situated, the branches grow apparently from 

 the base of the smooth upper margin. This character in a fair 

 degree distinguishes the plant, together with a few others, from 

 the rest of the Bactrophycus. 



The stems of the lateral branches are more slender than 

 those of the principal members. The leaves on them are pro- 

 portionately smaller, and very approximately disposed. These 

 leaves have in most cases the lesser ramulets arising from their axils 

 which sooner or later become provided with the receptacles. The 

 ramulets usually measure 2- 1cm. in length, but freijueutly do 

 not exceed one centimeter. 



Vesicles are found on the lower portions of the ramulets. 

 They are liable to a considerable variation in shape according 

 to the individual and to their position in the frond. As a rule 



