154 BRITISH MARINE ALG. 
variably found growing on the long stems of Laminaria digitata (Fig. 46). 
Rhodymenia palmetta (Fig. 141) is a rarer and very much smaller plant. 
It rarely exceeds 2in. or 3in. in height and breadth. Its pretty little 
fronds are usually fan-shaped, and are divided rather numerously by 
repeated forkings, which are rounded at their axils, the tips being pointed 
Fie. 142. Rhodymenia palmetta—var. Nicwensis, 
or tapered. The stem is long in some specimens, but very short in others. 
Tubercles are borne near the tips of the sezments or sometimes on their 
margins. Tetraspores are also produced in the terminal forks, and appear 
like little cloudy spots within the margins. This form of the species is 
usually parasitic on the stems of Laminaria digitata (Fig. 46). It is 
annual, and is found from May to August. The very pretty and distinct 
var. Nicwensis (Fig. 142) I have always found growing on rocks at extreme 
low-water mark. Our illustration was taken from a very perfect specimen 
found by me outside the Castle rocks at Hastings. In this species the 
fronds are tufted, and arise from a narrow horny stem ; the forkings are 
few, and the segments are cleft nearly to the base, each division being 
long, narrow, and rounded at the tips. The substance is at first very 
rigid, but it becomes soft and pliable in drying, and adheres very well 
to paper. The colour is brighter than that of the former plant, being of a 
beautiful rose-pink. The plant is a summer annual, and, like the fore- 
going, is widely distributed, but is usually considered a rarity, its 
diminutive size doubtless causing it to be frequently overlooked. Euthora 
cristata, which was formerly a Rhodymenia, is an extremely rare summer 
annual, found only on the northern coasts of this country, but pretty 
generally on the Scottish shores and at the Orkneys. This beautiful little 
plant, so rare in England, is one of the commonest species in America, 
where it is frequently found producing both kinds of fruit ; the tubercles 
being, however, generally observed on the upper margins of those with 
broad segments, tetraspores on specimens with narrow crested branches. 
Both of these forms of the species are represented at Fig. 143, the 
narrow variety being slightly enlarged. The fronds of this species are 
about 2in. high. Those of the narrow variety are usually divided into 
