OS SYXOrsiS OF BRITISH BEAWBBD8. 



cal, obtuse, oblong or dab-shaped, suddenly contracted at 



the base into a short Btem, thin and membranaeeous \ 



of finctification minute, roundish, Hook. Br. /'/. p.2. t >. 277. 



(Atlas, PL XII. Pig. 15.) 

 Asperoooccus bull \ ~. "Dub. Encceliuni 



bullosum, Ag. Ghutridium Opuntia, Lyngb. Diva Turneri, 



DUUo. 

 Huh. In tlif sea, on stones and the larger Algae, on r A 



etc., often growing in 4-5 fathoms. Annual. Summer and 



autumn. 

 Asperococcns Turner'/ appears to delight in land-locked 

 muddy bays, where it grows to a gigantic size. Specimens 

 upwards of three feet in length have been dredged by Mr. 

 Thompson in Strangford Lough. I have seen individuals 

 not much inferior in the little harbour of Dingle, and in 

 the long deep channel which separates Valentia from the 

 mainland. When growing in deep water, its favourite 

 habitat is on the stems and leaves of Zoster a. Specimens 

 gathered within the tide-range are of much smaller size, 

 not more than a few inches in length. Except in size it is 

 subject to little variation. It may always be known from 

 A. echinatus by its greater delicac}^ of texture, more evi- 

 dent reticulations, paler colour, and more obtuse and in- 

 flated frond. Named by Dillwyn after Mr. Dawson Turner, 

 the father of modern Phycology. 



48. echinatus (The prickly Asp>erococcus) ; frond cylindrical, 

 obtuse or acute, much and gradually attenuated to the base, 

 Grev. Alg. Brit. p. 50. t. 9. (Atlas, PL XII. Fig. 46.) 



Asperococcus fistulosus, Hook. A. vermicularis, Moore. A. ru- 

 gosus, Lamour. Encoelium echinatum, Ag. E. Lyngbyanum, 

 Grev. Scytosiphou fistulosus, Lyngb. 8. filum, var. fistulo- 

 sum, Ag. Ulva fistulosa, Huds. Conferva fistula, Roth. 

 Hal. On stones, etc., between tide-marks. Annual. Summer 

 and autumn. 

 A very common, but we cannot say a very beautiful 

 plant ; one of the least highly organized of the family to 

 which it belongs, and the coarsest in its mode of growth. 

 The only variation to which it is subject is the size, and the 

 more or less tapering extremities. The size varies so 

 greatly that very good observers have contended for two 

 species. 



XXV. LITOSIPHOX. 



49. pusillus (The small Litosiphon); fronds tufted, thread- 



