158 BRITISH SEA-WEEDS. \_MelanospennecB. 



liglit olive, tlicy are so dark as to be almost black : while 

 the Ayrshire ones were light olive, and almost as broad 

 as the featliers of a robin^s wing; those from the Frith 

 of Porth were like the greenish-black of a starling's wing. 

 In some specimens the greenness was increased by Striatella 

 arcuata, as a parasite. 



5. SpHACELARiA ciRRHOSA, Lijiighye. 



This is a very common kind, parasitical on larger Algae. 

 It is very variable in appearance. The most common kind, 

 however, may be seen about the end of summer, detached 

 from the other Algee, and floating in great abundance, hke 

 little round balls. It does not adhere well to paper. 



6. SpiiACELAiiiA FUSCA, Aganlk. 



This is a rare species, found in the south of England, and 

 in AYales ; it is beautifully figured in Phyc. Brit., PI. cxlix. 



7. Sphacelaria iiADiCANS, Harveij. 

 Hather rare, found in England and Ireland. 



8. Spiiacelaiiia racemosa, Greville. 



This is allied to the preceding, but is larger. 



Genus XXVIII. ECTOCAllPUS, L?/nohf/e. 

 Gen. Char. Filaments capillary, jointed, olive or brown. 



