Ser. GONGYLOSPERME^E. ( 187 ) Fam. CERAMIACEiE. 



Plate CXXVII. 

 CALLITHAMNION THUYOIDEUM.— 7/an;. 



Gen. Char. — Fronds filiform and articulated, sometimes at length in the older parts 

 cellular and partially opaque, single-tubed ; divisions mostly pinnate, dissepiments 

 hyaline. Fructification of two kinds, on distinct plants : 1. Favellje, mostly 

 lateral on the branches, and filled with minute spores ; 2. Tetraspores, external, 

 tripartite or cruciate. Name from KaXhs, "beautiful," and ddfxvos, "a slu-ub." 



Callithamnion thuyoideuin. — Fronds tufted, branched ; branches dis- 

 tichous, bi-tripinnated, fi-equently with secondary plumules, which are 

 long, linear, or linear-lanceolate ; articulations of the stem and branches 

 very variable, even in the same fi'ond, three to six times as long as 

 broad, shorter upwards ; tetraspores terminal on the pinnulee. 



Callithamnion thuyoideum. — ffarv. in Bool. Br. Fl. toI. ii. p. 346 ; Haw. P. B. 

 plate 269 ; Harv. Man. p. 181 ; Harv. Syn. p. 153 ; Atlas, plate 59, 

 fig. 275. 



Callithamnion thuyoides. — Aff. Sp. Alg. vol. ii. p. 172 ; Endl. 3rd Suppl. p. 34 ; 

 Kiitz. Sp. Alg. p. 645 ; /. G. Agardh, Sp. Gen. Alg, vol. ii. p. 44. 



Callithamnion tripinnatum. — Harv. in Hook. Br. Fl. vol. ii. p. 346 (not of 

 Agardh) ; Wyatt, Alg. Danm. No. 186. 



CoNPKRVA thuyoides. — E. Bot. t. 2205. 



Hab. — On rocks near low water. Kare. Annual. Spring and summer. Yarmouth 

 {Mr. Borrer) ; Plymouth (Mr. Boswarva, &c.) ; Pier, Torquay {Mrs. Griffiths) ; Falmouth 

 {Miss Warren) ; Ilfracombe and Bracelet Bay, Swansea {Mr. Rolfs) ; Wicklow {Dr. 

 Harvey) ; Portaferry {Mr. W. Thompson) ; Rouudstone {Mr. M'Calla). 



Geogr. Dist. — British Islands ; Atlantic coasts of France. 



Description. — Fronds single or scarcely tufted, slender and capillary, ' 

 one to three inches long ; branches distichous, closely and repeatedly 

 pinnated with regularly alternate plumules, which are long, generally 

 widest upwards, often fm*nished with secondary plumules, or occasionally 

 even with a third set, all bi-tripinnated, the pinnae and pinnulse longest 

 about the middle or towards the summit, shorter towards the base, giving 

 the frond a lanceolate or linear-lanceolate outline ; the ultimate pinnulee 

 short, cylindrical, somewhat obtuse ; all erecto-patent, and somewhat 

 closely placed. Articulations veiy variable ; those of the stem and 

 branches four to six times longer than bi'oad, gradually shorter upwards, 

 cylindrical, tapering veiy slightly upwards to an obtuse point. Substance 

 very soft and flaccid, closely adhering to paper. Colour, a very delicate 



