324: Mr George Traill on the 



and August. Rousay Sound ; and at Sac({uciy Head in Rousay ; 

 Calf Sound, 4 fathoms ; Widefirth ; Skaill Bay, West Mainland, 

 &c. Often attains the length of 14 inches. 



[MICROCLADIA, Grev. 



147. Microcladia glandvilosa (Soland.), Grev. 



Usually on rocks. Algae, or sponges, either near the low-water 

 mark of spring tide or at a gi-eater depth. Rare. Annual. The 

 only Orkney specimen I have seen is a small one, in fruit, found 

 by Dr M'Bain, now in my collection. 



CERAMIUM, Lyngb. 



148. Ceramiiun acanthonotum, Caim. 



On rocks in the shade from about half-tide level to near low- 

 water mark. Not in pools. All the year. Fruit in winter and 

 spring. Rousay, near Westness, fine ; Birstane Pier, &c. The 

 so-called " Ceramium ciliatum " of M'Bain should, probably, be 

 referred to this species. 



149. Ceramium echionotum, J. Ag. 



Usually on rocks and stones, and in pools, between tide marks ; 

 epiphytic on Algse. Annual. Summer and autumn. One speci- 

 men in Mr PoUexfen's collection. 



150. Ceramium ciliatum, DucUiz. 



Usually in pools between tide marks ; epiphytic on Algse. Some- 

 times in places left uncovered by the tide at low water. Annual. 

 Summer. Mentioned by Harvey as found in Orkney. 



151. Ceramium diaphanum (Lightf.), Roth. 



On rocks, and epiphytic on small Algse, in pools between tide 

 marks. Always submerged. Annual. March to September. 

 Fruit in July and August. Fine at Quoy Bay, Hoy ; good at 

 Kirkwall Bay, opposite Iceland Skerry ; at Inhallow. 



152. Ceramium. tentiissimum, Chauv. {Ceramium iwdosum, Griff, and 



Harv.) 



Usually occurs on sandy shores ; epiphytic on small Algse and on 

 Zostera marina. Annual. Summer. Found by Mr Pollexfen in 

 Kirkwall Bay ; epiphytic on Cerammm rubrum. Named by Mr 

 Batters. 



153. Ceramium Deslongchampsii, Chauv. 



Occurs on rocks between tide marks, and epiphytic on the 

 smaller Algse. Usually in pools. All the year. Fruit, July, 

 August, September. Inganess Bay ; Carness ; Rousay, in pools 

 east of Providence Gjio. 



154. Ceramium rubrum (Huds.), Ag. 



On rocks, and epiphytic on Algae, in pools between tide marks. 

 Always submerged. All the year. Fruit in summer. The variety 

 proH/f'Tiwi {= C. decurreus, Harv.) also occurs at Kirkwall Bay, 

 Rousay, &c. 



