PI. cell. aph. 2.THALASSIOPHYT7E. 35. Sphacel. 333 
3. Sphacelaria Merteiisli . Merten's rust-weed. 
Thatlus branched, yellowish brown; branches 'pinnate; 
lobes mostly opposite, short; joints half as long as broad. 
Conferva Mertensii, Engl. Bot. 999 ; Dillw. Syn. 79. 
Tufts 3 inches high; stems many, cylindrical, pinnate; 
branches short, opposite, 2-rowed, from the base of th^ 
stem; pellucid. 
4. Sphacelaria ccespitula. Small-tufted rust-weed. 
Thallus tufted, very small; branches mostly simple, al- 
ternate, long, blunt. 
Conferva olivacea, Dillw. Syn. 57. 
Sphacelaria caespilula, Lyngbye Hydr. Dan. 106. 
On other sea-piants. 
Threads about a line high, aggregated, yellowish green. 
5. Sphacelaria fusca. Brown rust-weed . 
Thallus threadlike; branches distant, mostly alternate; 
twigs spreading, clublike; joints transversely banded in the 
middle, as long as broad. 
Conferva fusca, Huds. FI. Angl. 602 ; Dillw. Conf. 95. 
Stones and rocks in the sea. 
Threads 3 or 4 inches long. 
XI. 36. ELLISIUS. Ellis. 
Thallus rose-red, branched ; main stem solid, continuous, 
or slightly jointed; branches and twigs scattered, jointed; 
joints of the twigs simple, composed of one tube; thecce 
ovate, lateral, or immersed in the tip of the branches. — 
Marine. 
1. Ellisius glaber . Bald ellis. 
Threads much branched, red ; stem thick, jointless, net- 
like, naked below, very much branched above ; twigs 
crowded, nearly in whirls, short, alternately branched, 
jointed ; joints as long as broad. 
Conferva Arbuscula, Dillw. Conf. 85; Engl. Bot. 1916. 
Sea-shore. 
Thallus tufted, 2 inches high. 
