Marine Alga' of Berwick-on-Tweed. 279 



Family — S phacelariacese. 



BATTEESIA, Eke. MSS. 



Battersia mirabilis, Rice. Mscr. 



Fig. ,, „ Tab. Nostr. ix., figs. 1-4. 



Hab. On Balfaue. Jan. and Feb. Rare. Berwick Bay, Scremerston. 



A minute species forming small yellowish-brown patches on 

 Half sice. To the naked eye it closely resembles the fructification 

 of the host plant, and no doubt has often been passed over as 

 such. The filaments are simple or furnished with a few short 

 branches given off at wide angles, both primary fronds and 

 branches usually ending in a sporangium. The fronds are 

 monosiphonous, or very slightly polysiphonous below ; they 

 appear to grow down into the tissues of the host plant, and it 

 is by no means an easy matter to distinguish between the cells 

 of the Ralfsia and those of the parasite. The filaments are 

 usually closely packed together forming a sort of microscopical 

 turf over the surface of the Ralfsia. The growth is from an 

 apical cell as in Sphacelaria, otherwise the plant closely resembles 

 a Streblonema or an Ectoearpus. 



SPHACELAEIA, Lyngb. 



Sphacelaria aESPiTULA, Lyngb. 

 Hydr. Dan., p. 105. 



Descr. Spbacelaria cnespitula, Lyngb., I.e. 



Fig. „ „ Lyngb., I.e. t. 32a ; Tab. nostra rx., fig. 5-8. 



Exsicc. ,, ,, Holmes, Alg. Brit. Rar., no. 48. 



Syn. „ „ Ag., Spec. Alg. ; './. Ag., Spec. 



Hab. Epipbytic on the stems of Laminaria hyperborea (L. Cloustoni Le 

 Job) Jan.— Oct. Fruit Jan. and Feb. Rare. Berwick Bay. 

 Near the Coves. 



To this species I have referred, with considerable doubt, a 

 rare Sphacelaria which grows on the roots of Laminaria hyperborea. 

 The tufts are small and scattered, the filaments very short, 

 \isually from the sixteenth to the eighth of an inch high, either 

 simple or furnished near the apices with one or two short simple 

 branches. The plurilocular sporangia are large and oval, secund 

 on the inner sides of the filaments and very numerous. They 

 are borne on short pedicels composed of three cells, not of a 

 single cell as is usually the case in Sphacelaria cirrhosa. The 

 articulations are slightly broader than long. 



