396 Mr G. W. Traill on Marine Algoe of Joppa, 



this difficulty may be overcome by sprinkling skimmed 

 milk over the specimens before pressing them. 



Diatoms are often found attached to this alga in such 

 profusion as entirely to hide the host plant. Of these, 

 Rhabdonema arcuatum, Synedra ajfflnis and GraminatopJwra 

 marina are amongst the most frequent. 



Bryopsis plumosa. — This occurs in considerable abund- 

 ance in pools a little below half tide. It is a summer 

 annual, and is in best condition in July and August. 

 Many of the plants are of great luxuriance and size, and 

 compare favourably with those from the southern shores of 

 England. The best way to mount specimens is to lay 

 them out on paper under sea-water in the usual way, and 

 then fix them on a board, allowing them to dry thoroughly 

 without pressure. Their beautiful glossy green is by this 

 means retained. 



Callithamnion strictuvi, Ag. — This rare species I found 

 for the first time in 1880 on rocks uncovered at the lowest 

 spring tides only. On my sending specimens to Bornet of 

 Paris they w^ere identified by him, in the absence of fruit, 

 as Callithamnion strictum, which is new to the British 

 flora. 



Callithamnion corymhosum, Ag. — Tins species I found 

 for the first time in June 1882, when it was in good 

 fructification. It occurs on muddy rocks uncovered at very 

 low tides only, and there is a fresh water stream at the 

 place. The plants are of as fine a colour as any I have 

 seen from the south coast or from Ireland. 



Tilopteris Mertensii. — This handsome species occurs on 

 muddy stones and rocks at low water. It is always sub- 

 merged. I have usually found the finest sporangia in June. 

 The Joppa specimens, though smaller than those from 

 southern localities, are generally perfect, and of good 

 colour. 



