83 



Chapelle, lacunes vaseuses au milieu des madrepores, Mazè n° 488Ó/.Ï in Herb. Mus. Brit. ! — 

 West Indies, Scrivener collection in Herb. Mus. Brit.! - "Carolina, Bermuda and Cari- 

 bees" Clerk in Herb. Sloane vol. 318. fol. 48! — "PI: Centro-Americ.'" Oersted in Mus. 

 Bot. Copenhagen ! — No locality, sub nom. *Nesea Penicillus" in Herb. Chauvin\ — No 

 locality, sub nom. "iVesea penicillus Lamx. Penicillus capitatus Lamk. Coll. de Lamarck" 

 in Herb. Mus. Paris) - No locality, Lord Valenticis collection in Herb. Mus. Brit.! 



forma clongata. 



Hab. ATLANTIC. Banc de Bahama, Herb. Lamouroux ! — Bermuda, Farloiu in Herb. Collins ! - 

 Bermuda, in the ponds of Walsingham (having subterranean communication with the sea), 

 Howe n" 119! — Key West, Hooper in Alg. Exsicc. Am. Bor. Farl. Anders. Eaton, n" 43 

 (pro parte) in Herb. Mus. Brit.! - - Florida, Key West, Howe n° 1533! -- St. Croix Bór- 

 gesen ! — Guadeloupe, Saintes, Anse du Marigot, dans Ie sable, sub nom. P. elongatus, 

 Mazé, n° 166, ière sér. and n° 1073! 



Stipes simple, very rarely branched, of varying length (2.5 — 14.5 cm.), narrow (3 — 5 mm.), 

 cylindrical, occasionally becoming wider above, hard, rigid, thickly encrusted, smooth, with 

 surface minutely pseudoporose (under microscope). 



Capitulum globose or sometimes oblong, 2 — 6 cm. in diameter. 



Filaments of capitulum densely crowded, slightly entangled, ascending, sometimes spreading 

 below, thickly encrusted, rigid, slender, 100 — 300 u in diameter; branchlets sometimes shortly 

 subtorulose or here and there constricted ; apices slightly swollen, often subtorulose. 



Filaments of stipes bearing lateral appendages 4 — 5 times dichotomously divided, and 

 terminated by very small short truncate apices. [Figs. 164 — 168]. 



forma typica. 



Corallina Penicillus Ellis and Solander, loc. cit. 



Capitulum dense ; filaments generally 100 — 200 p. in diameter. Stipes about 4 — 8 cm. 

 long, usually not penetrating to middle of capitulum. [Figs. 164, 165, 168]. 



forma elongata. 



Penicillus elongatus Decaisne, loc. cit. 



Capitulum narrow, oblong, often interrupted or prolonged below ; filaments generally 

 200 — 300 ij. in diameter. Stipes elongate, 5.5 — 14.5 or more cm. long, penetrating beyond 

 middle of capitulum. [Figs. 166, 167]. 



P. capitatus is the commonest species of the genus, and was figured in literature as 

 long ago as 1734 by Seba. Though it is apt to vary in the size and shape of the capitulum 

 and the length of the stipes, the specific characters are fairly constant. The filaments are 

 slender, very numerous and well-calcified ; and the stipes is thin, hard, rigid and round; is 

 commonly 7 — 10 cm. long, and very rarely is branched. Harvey, who admitted only three 

 species in Penicillus proper, took a broad view of P. capitatus, and, as his herbarium shows, 

 included under this species anything intermediate between it and P. dumetosus. The delimi- 

 tation of the species is simplified by an examination of the stipes, the cortex of which under 

 the microscope (see p. 75) is seen to be minutely pseudoporose (fig. 168a), while that of 



