554 XEMALIONACEAE. 



4. ASTEROCYTIS Gobi, Trud. St. Peterb. Obsht. Yest. 10: 

 85. 1879. [Not seen.] 

 1. Asterocytis ramosa (Thwaites) Gobi, loc. cit. 



Filaments 0.5-1 man. long, mostly 13-28/* in diameter, sparingly dichot- 

 omous; vegetative cells (protoplasts) 5-10 p. long, 1-2 times as long as broad, 

 chromatophore vaguely stellate or indeterminate; cysts (akinetes ?) subglobose, 

 ovoid, or ellipsoid, uniseriate or rarely in a double series, 13-19 p. in longest 

 diameter (including walls), their walls 2-5 p, thick. The monospores or akinetes 

 of the Bahamian specimens resemble in form those shown by Wille in his /. 10 

 (Xyt. Mag. Naturvidensk. 38: pi. 1. 1900). 



On the older parts of Polysiphonia hapalacantha, Great Exuma : apparently of 

 wide distribution ; American Virgin Islands. Type from England. 



Family 2. NEMALIONACEAE. 



1. LIAGORA Lamour. Xouv. Bull. Sci. Soc. Phil. 3: 185. 1812. 



Branching dominantly dichotomous (dichotomy sometimes obscured by proliferations, 

 especially in Nos. 1 and 3) ; dioicous. 

 Assimilatory filaments cylindric, 13-21 a in diameter in distal parts, projecting 

 beyond the calcification and forming a more or less conspicuous rufous or ful- 

 vous superficial nap ; antheridia in isolated compact, conic- 

 ovoid, subglobose, or hemispheric tufts 40 65, broad. 1. L. farinosa. 

 Assimilatory filaments more or less moniliate, 3-13 in diam- 

 eter in distal parts, a superficial nap wanting or incon- 

 spicuous : antheridia in rather loose flabellate or funnel- 

 shaped clusters 10 20 , wide, commonly forming an ap- 

 parently confluent and continuous peripheral stratum. 

 Surface of thallus in dried state smooth and compact or 

 minutely pitted : cystocarp with a rather inconspicuous 

 and poorly defined involucre. 2. L. valida. 

 Surface of thallus in dried state alveolate, farinaceous, or 

 pulverulent ; cystocarp with a sharply defined basal in- 

 volucre of long ascending or partly encircling filaments. 3. L. ceranoidcs. 

 Branching dominantly monopodial.* 

 Monoicous. 



Calcification axial, the distal ends of the assimilatory fila- 

 ments free; antheridia in compact tufts 25 40 broad, 

 on penultimate or antepenultimate segments ; cystocarp 

 with an involucre of ascending filaments. 4. L. pinnata. 



Calcification chiefly and primarily extra-peripheral ; an- 

 theridia in small tufts, mostly 13-20 u broad, on ulti- 

 mate and penultimate segments ; involucre of cystocarp 

 represented by a few pendent or appressed-decurrent 



rhizoidal filaments or wanting. 5. L. pedicellata. 



Dioicous ; calcification usually light, chiefly axial ; plant very 

 flaccid and mucous ; assimilatory filaments usually beauti- 

 fully moniliform ; cystocarp with an inconspicuous involucre 

 of ascending filaments. 6. L. mucosa. 



1. Liagora farinosa Lamour. Hist. Polyp. 240. 1816. 



Liagora elongata Zanard. Flora 34: 35. 1851. 



Liagora Cheyneana Harv. Trans. Roy. Irish Acad. 22: 552. 1855. 



Liagora lurida Dickie, Jour. Linn. Soc. Bot. 14: 195. 1874. 



Liagora crassa Dickie, loc. cit. 



L-iagora cayohuesonica Melvill, Jour. Bot. 13: 262. 1875. 



Liagora farionicolor Melvill, loc. cit. 263. 



Liagora corymbosa J. Ag. p. p. max., Anal. Alg. Cont. 3: 104. 1896. 



Extremely variable in size and in habit of branching, but constant in the 

 large compact capitate tufts of antheridia, dioicously disposed, in the protrusion 



* Occasional conditions of L. farinosa may be sought here. L. decussata Mont., 

 not yet reported from the Bahamas, has its branches commonly denudate at base 

 and 'thus apparently stipitate or articulate, which is not true of the other West 

 Indian members of the monopodial group. It differs also in being more compactly 

 calcified, less mucous, and less adherent to paper when dried. 



