which they appear to be homologous. Colour a brownish olive. Sub- 

 stance cartilaginous. In drying this plant shrinks considerably, and 

 closely adheres to paper if pressed. 



Common on all our rocky shores, first appearing about April 

 or May in the form of little, pea-like buttons, attached to small 

 Algae, or grouped in clusters on the surface of rocks and coral- 

 lines, and, as the season advances, gradually acquiring size ; the 

 fronds becoming hollow and cohering in masses. In its young 

 state it constitutes, according to Areschoug, the Corynojphlaa 

 baltica of Kiitzing. Not having seen any specimen of the plant 

 so named, I am unable to decide the question. 



By most continental authors the specific name marina is 

 adopted for this plant, a name which I find for the first time 

 in Agardh's Dispositio Algarum Suecice, published in 1811. 

 Areschoug alone adheres to the older Linnsean name difformis, 

 and if either of these be adopted, the latter is surely preferable, 

 not" merely from its elder birth, but because it expresses a 

 natural character of this deformed-hoking or double-faced plant, 

 while marina applies alike to every species of the genus, and 

 even of the family (Chordariece) to which it belongs :— so that 

 one might as well talk of a marine sea-weed as of a marine 

 Leathesia. I adopt the name selected by the founder of the 

 genus, and which dates from 1809 (E. Bot. t. 1956), because 

 it well expresses the aspect of the plant, — " like a cluster of 

 small potatoes/' — and is at least two years older than marina. 

 It is strange that Sir J. E. Smith should have overlooked the 

 Tremella difformis of Linnaeus, if that plant were rightly taken 

 up by Hudson and Lightfoot. 



Fig. 1. Leathesia tuberiformis, in various stages : — the natural size. 

 2. Portion of a longitudinal slice, showing the dense coloured outer wall, 

 or crust, and some of the cobwebby fibres. 3. Apices of the cobwebby 

 fibres, and some of the club-shaped filaments. 4. Some of the same, with 

 scores : — all more or less highly magnified. 



