THE FUCACE.E OF JAPAX. 33 



hardly exceeding 10 cm. in Iciigtli. They are decompoiindly 

 alternately divided, with the lower lacinioc terete fdiform; the 

 upper ones may develop into ordinary leaves. As a rule, they 

 are sterile and not provided with vesicles. Occasionally, however, 

 the apex of a leaf is inflated into au ovate mucronate vesicle. 

 The branchlets from the middle and the upper portions develop 

 further and constitute the principal parts of the frond. They 

 are decompoundly subpinnately ramose with leaves or sterile 

 ramules at the base ; the ultimate segments become vesiculiferous 

 and, when mature, are fertile. The leaves are linear-lanceolate, 

 acuminated above, and taper downwards into a short, flat stipe : 

 they are ribless, entire, and destitute of cryptostomata. 



Vesicles are ellipsoidal or ovate, occasionally fusiform. They 

 are sometimes solitary but 2-5 or more of them are found in a 

 moniliform series at the terminal portion of a vegetative segment. 

 The constrictions between two successive vesicles are loose and 

 seldom stalk-like. The inferior end of the lowermost vesicle of 

 a series tapers downwards into a long filiform stipe, and from 

 the upper end of the uppermost vesicle, a racemose receptacular 

 ramulet rises. Each receptacle is lanceoid-cylindrical, verruculose, 

 accuminate above and with a filiform stipe below. 



Remark on the affinity to other species. There are six species 

 hitherto reported from the north Pacific Ocean, w^hich have some 

 relation to the present species, viz: — Cyüophyllwni crassipes J. Ag., 

 Cystophyllum geminatum J. Ag., Cystophyllum Lepidium Harv., 

 Gyslophyllum filifoUum J. Ag., Cystoseira spicigera Ag., and 

 Oystoseira hypocarpa KiJTz. Among^these^six species, Cystoseira 

 hypocarpa Kütz. is probably synonymous with Oystopliyllum Lepi- 

 dium Harv. as De Toni^^ has already pointed out; and Cystoseira 



1) De Toni: Syll. Alg. III. p. 175. 



