iMiK i'r('Aci:.E or .iapan. 2B 



seas and never come down so far south as the coast of Simoda 

 washed by the warm Japan current. The plant which Dr. 

 Okamura identified with Harvey's species and distributed in 

 the "Algœ Japon i ere Exsiccatœ" No. 37, is limited to the warm 

 part of Japan. lîut this is quite a distinct plant, being described 

 in the present paper under the name of Ishige Okamural. The 

 Hongkong specimen, (if any plant of such form as is referable 

 to the forma here described occur there), may probably be the 

 same as Ishige Okamural. But in the herbarium of Trinity 

 College the specimen is lacking and I am unable to enter into 

 any discussion of it. 



This forma is more common in the middle part of Hokkaido; 

 and in its characters gradually approaches /. iypica on one side 

 and /. japonica on the other, as we trace it westward and east- 

 wards respectively. Details relating to this circumstance will be 

 given in later paragraphs. 



/. japoniea form. nov. Plate I. Fig'. 5. 



Diagnosis. Fronde anaustiore compresso-plana decomposite dichotonia fasti- 

 iriata; vesiculis oblongis vel bilobis in ramis superioribus infra axillas 

 inflatis ; receptaculis Hnearibus truncatis terminalibus complanatis sim- 

 plicibus vel furcatis. 



= Pelvetia japonica Yendo.: Prelim. List of Jap. Fiic. p. 151, 



The frond of this forma is thinner and narrower than that 

 of /. typiea. and more resembles /. Babingtonii in this respect. 

 The vesicles are oblongo-obovate, with a diameter sometimes 

 more that twice as broad as the segment and considerably 

 swollen on both surfaces so that they show a remarkable appear- 

 ance in the dried specimens. They are, as a rule, found at the 

 terminal portions of the upper segments, the inflation very often 

 running into the ujiper two segments. Receptacles are linear, 



