( 19G ) 



filiform marine Alga), is one of the many interesting discoveries which 

 we owe to Mr. Lilly Wigg, of Yarmouth, who first gathered it in the 

 year 1799. It was 'named by Mr. Turner, in compliment to the late 

 celebrated Professor Mortens, of Bremen." — Fhyc. Brit. 



This fine species, at one time so much sought after on account of its 

 rarity, is still as much admired for its beauty ; and although now found 

 in very many places on the British shores, is by no means abundant. 

 We have received beaiitifully fruited specimens from the E,ev. James 

 Yuil, of Peterhead, and others equally beautiful, though barren, from the 

 coast of Ayrshire. 



In our Peterhead specimens, the ramuli often contain several spores, 

 placed the one above the other in a string, thus occupying almost the 

 whole of the ramulus, and in these the spores are occasionally single, 

 although they are mostly binate. 



No other British species of the genus can be at all confounded with 

 the present ; its beautifully doubly pectinated ramuli are strikingly 

 characteristic, and indeed more closely assimilate the plant to some of 

 the Bpliacdarm than to any of the other species of the present genus,- 



EXPLANATION OF PLATE CLXXXIL 



Fig. 1. — Ectocarpus Mertensii, natural size. 

 2. — Braucli. 



3. — Portion of same ■\vitli fruit. 

 4. — Same. All magnified. 



