NOTES ON RANGE IN DEPTH OF MARINE ALG&. 151 
* Silliman's Journal,’ Count Pourtales states that Centroceras clavulatum 
came up in a dredge which had been at the bottom in 270 ‘fathoms 3 
this species is stated in * Nereis Americana’ as abundant at Key West, 
everywhere near low-water mark. I doubt very much whether this 
plant was brought from the bottom ; most likely it was caught by the 
dredge in its progress towards the surface. In Areschoug’s ‘ Phyceæ 
Seandinavicee Marine,’ it is stated that Desmarestia aculeata has been 
got, between Jutland and Norway, at a depth of 90 fathoms. 
In the supplement to Captain Inglefield’s ‘Summer Search for Sir 
John Franklin’ (1853), there are some cases which were recorded by 
myself in the Botanical Supplement to the work. They were given on 
the authority of Dr. P. Sutherland, from whom I received the speci- 
mens, viz. :— 
Fathoms. 
Fucus vesiculosus . . . . 40to 
Desmarestia aculeata . 2 805 100 
Dictyosiphon fueniculaceus - 58 5 I00 
A . 10, 100 
Laminaria eris aiei DU aa TOO 
Chordaria flagelliformis . . 80 ,, 100 
Chetopteris plumosa . 25 „ 30 
Ectocarpus a ©. 70 , 80 
Euthora cristata 98 ,, 100 
Ptilota serrata oci cU 
Kalymenia Pennyi. . . . 20, — 
Conferva Melagonium . . 20, — 
Respecting the greater depths in the above list, I have much doubt. 
It is a well-established fact that masses of Alge are set adrift by the 
action of the ice in summer, and are seen floating in great masses. 
Under such circumstances, though the dredge may have been at the 
bottom in 100 fathoms, it is rash to conclude that all its contents, 
especially 4/ge, have been growing at that depth. 
uring the voyage of the * Fox,' under the MERE of Sir L. 
M*Clintock, Dr. Walker dredged Rhodymenia interrupta at the east end 
of Bellot Strait, in about 60 fathoms as estimated; the plant is now 
known to be an Arctic form of Phyllophora Brodizi, and this is of 
some interest in relation to the probable existence of the plant at 80 
fathoms on the Irish coast, already alluded to. Captain Thomas 
Mitchell, late commander of the * Queen of Nations,' belonging to Aber- 
deen, gave me some material which eame up adhering to the sounding- 
