] 86 THE BOTANICAL MAGAZINE. [Vol. xxxi. No. 367. 



Monostroma pulchrum Farl. 



Mar. Alg. New Engl., p. 41.— De Toni. Syll. Alg. I, p. 110.— 

 Collins: Green Alg. N. Amer., p. 211. — Coll., Hold, et Setch. : 

 Phyc. Bor.-Amer., No. 658. 



= Monostroma undulatum f. Farlowii Fosl. : Mar. Alg. Norway, 

 Contrib. I, p. 114. 



My specimen fairly coincides with here mentioned species 

 in its general appearance and in structure, and can not be 

 dealt with in any other way than to identify with it. 



The plant resembles so much in its outward appearance 

 M. undulatum Wittr. as to justify the reduction to the 

 latter's forma as has been ever done by Foslie. But after a 

 comparison of my specimen with those from Kjollefjord and 

 Hjelmso, sent from Foslie under M. undulatum Wittr., as 

 well as a specimen distributed as No. 658, Phyc. Bor.-Amer. 

 under M. pluchrum Farl., I have come to the conclusion 

 that it is more advisable to mention Farlow's species in an 

 independent rank to keep the uniformity of specific values of 

 the co-generic members. In the typical form of M. undulatum 

 Wittr., cells are angulate and very compactly arranged, 

 while in M. pulchrum Farl , they are more or less roundish 

 polygonal and less compactly so ; in the former, thickness of 

 frond measures 40-50 /u, height of cells 19-22 [-i, and in the 

 latter, described to have thickness of frond 6-15 ;j. only. 

 Foslie has not observed any intermediate measurement be- 

 tween the extremities. Unless too much stress had been put 

 on the external appearance of frond, the differences here 

 pointed out are ample enough for specific distinction of Mono- 

 stroma acknowledged by the modern algologists. It seems 

 curious to me to find that Collins in the Green Algae of 

 North America, p. 211, treated M. pulchrum Farl. as a 

 valid species in spite of M. undulatum var. Farlowii Fosl,. 

 separately mentioned on the same page. The specimen dis- 

 tributed as No. 722, Phyc. Bor.-Amer. under the varietal 

 name is surely different from M. pulchrum Farl. 



