150 SEAWEEDS. 



induced naturalists to place them among zoophytes for a 

 long time, and it has been only recently discovered that 

 when the lime is cleared away by acid a vegetable struc- 

 ture is found beneath. 



The delicate thread-like fronds of the red Jania {Plate 

 II., Jig 6), parasite on a withered morsel of Ehodomela 

 were lying high and dry among waste ; slender as these 

 much forked branches are, they are coated with lime, 

 and of firm texture, (Jania rubens). 



We were not astonished to find Nullipores on that 

 coast, but it is always difficult to me to realize that the 

 clumsy coral-like branches of the Melobesia polymorpha 

 belong to the vegetable kingdom. Such is, however, the 

 case, and we were glad to place the Nullipore in question 

 among our collection of Algae. There are other species 

 of Melobesia, some growing on rocks in deep water, others 

 incrusting shells, etc., and some so small as to form mere 

 lichen-like patches on sea-weeds. The importance of this 

 group is considerable, we are told by Dr. Landsborough 

 that " the mortar used in the building of the Cathedral 

 of Iona was formed of calcined shells, and a great quantity 

 of the fragments of the white coral, which abounds upon 

 the shore of the island," he further adds that it is easier to 

 break the stones than the cement. He also gives a very 

 interesting account of the bivalve Lima, who, having the 

 same taste as St. Columba, builds himself a house binding 

 together morsels of Nullipore with a cordage of his own 

 manufacturing, and here he lives in safety among neigh- 

 bours from whose voracity his slender shell would afford 

 but scant protection. 



The Hildenbrentia is a crustaceous weed like a dull 



