DICKIE 



243 



Of the species enumerated "herOj tlie following are truly Arctic : 

 Sphacelaria arctica^ Kallymenia Pennyi, Halosaccion Ditmonti' 

 oides, Poli/siplionia arctica^ and PhijUopliora interrvpta^. 



Our data are not sufficient to lead to any general conclusions 

 as to species confined to tlie western side of the straits, or those 

 peculiar to the east side ; Callithamnion Americanum and Kally- 

 menia Pennyiy however, are worthy of mention as hitherto known 

 only on the west side. 



Compared with the Antarctic sea, tlie Arctic is remarkably 

 rich in species, if we are to jndge from the very few recorded in 

 the ' Flora Antartica ' as found there. 



M 



In conclusion, three products usually plentiful in certain marine 

 Algae of low^ latitudes are also abundant in some of the Arctic spe- 

 cies — yiz. iodides, Mannite, and carbonate of lime. With respect 

 to the latter, I need only allude to the presence of Mclohesia and 

 Corallina officinalis. Laminaria saccliarina^ as its name indicates, 

 yields IMannite, which appears as a white effloresence on the sur- 

 face when the plant is roughly dried without being washed; but 

 in this it is far exceeded by Laminaria lonyicniris, from which I 

 have been able to procure the same product in plenty. The pre- 

 sence of iodides I have also tested on Arctic specimens with the 

 following results, it being premised that a filtered and concen- 

 trated solution from a few grains of ash, with nitric acid and 

 starch, is generally sufficient to give in a rough way proof of the 

 amount of iodides, as indicated by tints varying from dark blue 

 through purples to pale rose ; and wdiere iodides are in small pro- 

 portion, the latter colour may not appear till after a few minutes : — 



Fucus nodosuSy pale purple ; 



F, vesiculostis, pale purple ; - : 



Diciyosiphonjheniculaceus, very dark blue; 



Laminaria longicruris, pale rose ; 

 . Ptilota serrata, pale purple ; 



Ahnfeldtia plicata, pale rose ; 

 • I^olysipTionia arctica, pale rose ; 



TJlva latifolia, pale rose, slowly ; 



Conferva Melagomnm^ pale purple. 



* Among the numerous Phsenogams of the Arctic regionR, only one is, I 

 believe, peculiar, viz. Fleuropogon Sabini. 



