SEAWEEDS. 169 



very silky. The C. albida grew near it, its long slender 

 branches densely crowded. These were all the members 

 of the large family of Cladophora which we succeeded in 

 finding. 



Arran had provided us with three Confervae, the family 

 characteristic of which is the simple thread shaped, un- 

 branched fronds. They are all articulated, some very 

 evidently so, and the fruit is contained in the articulations. 

 The first Conferva we found was like a lock of very 

 coarse horse hair ; of a dull green colour, curled, and 

 much entangled ; it was on swampy ground, where a 

 little rivulet discharged itself, and the tide occasionally 

 washed over ; it was Conferva litorea. We also found 

 the long, straighter and less clustered threads of C. 

 melagonium, (Cut I., Jig. 7), and a green coating on the 

 other weeds proved to be the delicate twisted threads of 

 C. tortuosa, (Cut I., Jig. 6). This family completes the 

 order of Confervacese. 



That of Ulvaceas succeeds it. We have here broad 

 expanded fronds as a rule, and thread-shaped ones as an 

 exception. 



The family of Enteromorpha have tubular fronds. E. 

 intestinales is a handsome weed, with fronds sometimes a 

 foot and a half long, and an inch broad ; it is of a full 

 green when fresh. E. compressa is very common, we 

 found its fronds in tide pools at Oban, Arran, Ardrossan, 

 and the Firth of Forth, varying from a thread to a half 

 inch in breadth. It is distinguished from the former 

 species by being branched, while the fronds of E. 

 intestinalis are always simple. The fronds spring from 

 one base, and gradually widen ; they are blunt at the ends. 



