556 NEMALIONACEAE. 



5. Liagora pedicellata M. A. Howe, sp. nov. 



Thallus usually very soft and flaccid, 4-16 cm. long or high, irregularly 

 monopodial, the main divisions paniculate or pyramido-paniculate, each branch 

 surrounded in the living state by a soft mucous sheath about as thick as the 

 whole diameter of the enclosed branch, this sheath showing a flocculent precipi- 

 tate of microscopic calcareous granules arranged mostly in the walls of irregular 

 alveolae, making surface in dried state minutely alveolate or farinaceous- 

 alveolate ; branches for the most part progressively shorter, varying from rather 

 sparse to crowded, tapering slightly to obtuse or subacute apex, 1.2-2 mm. broad 

 towards apex, including more or less calcified mucous sheath, 0.450.8 mm. 

 without sheath; central axis in basal parts 1.52.5 mm. in diameter, more or 

 less calcified and often denudate, in ultimate branches mostly 150175 fi in 

 diameter, usually readily visible after decalcification, commonly reduced to about 

 four filaments towards apex, the cells subeylindric-ellipsoid or dolioform, 104- 

 340 m X 36-104 /x, descending rhizoids 8-13 xt in diameter few in younger parts; 

 fascicles of assimilatory filaments mostly 300-600 /a long, 4-7 times divided, 

 usually subtrichotomous at one or two of the proximal articulations, otherwise 

 dichotomous, intermingled in older parts with simple or subsimple filaments 

 8-11 cells long, all filaments submoniliate in distal parts, the distal or subdistal 

 cells mostly obovoid, 15-26 ti long, 12-16 (20) /x broad; apical hairs numerous, 

 slender, long and flexuous, often cylindric-capitate, soon gelatinizing, leaving 

 inconspicuous vestigia; monoicous; antheridia in small inconspicuous tufts 

 mostly 13-20 /x broad, on ultimate and penultimate segments; carpogonial branch 

 straight, 20-25 xi broad, of 46 cells (including the usually long pedicel cell) 

 situated terminally or subterminally on the third or fourth segment of the 

 fascicle; cystocarp compact, subhemispheric, 90-215 xi broad, peripheral, ter- 

 minating a rather stout and rigid submonopodial axis or pedicel 300-450 xi 

 (4-8 cells) long, involucre wanting or represented by a few short appressed- 

 deeurrent or pendent rhizoidal filaments; carpospores obovoid, ellipsoid, or pyri- 

 form, 23-39 xi X 15-21 xt. 



On more or less exposed rocks, near the low-water mark (also found washed 

 ashore), Cockburn Harbor, South Caicos (Howe 555J, type), Malcolm Road, South 

 Caicos, Atwood Cay, Mariguana, Rose Island, Whale Cay, Great Bahama : Florida 

 (Boot Key). 



Liagora pedicellata is allied to L. pinnata Harv., in general habit, but differs 

 constantly in being more flaccid and mucous, in the more external or sheathing 

 (usually lighter) calcification, in the smaller simpler more terminal tufts of anther- 

 idia, in the straighter, more terminal carpogonial branches, in the more peripheral, 

 more obviously pedicelled, more compact and homogeneous, large-spored cystocarps, 

 which are destitute of a proper ascending involucre. In L. pedicellata, the calcifica- 

 tion is mostly in the external mucous sheath, extending irregularly down among the 

 peripheral filaments in the older parts : the distal ends of the filaments are covered 

 by it with the possible exception of the tips of the hairs in the apical region. In 

 L. pinnata the calcification is in among the filaments, the distal ends of most of the 

 filaments, with or without hairs, remaining free or protruding beyond the calcifica- 

 tion. The essentially terminal rather than lateral carpogonial branches might be 

 regarded by some as sufficient ground for placing the plant in the genus Trichogloea 

 rather than in Liagora, but in habit and other characters the plant is essentially a 

 Liagora, bearing, in fact, so close a resemblance to L. mucosa that a microscopic 

 examination is commonly necessary for their separation. 



6. Liagora mucosa M. A. Howe, sp. nov. 



Thallus very soft and mucous, lightly and irregularly calcified, 5-20 cm. 

 long or high, irregularly monopodial, the main divisions paniculate or pyramido- 

 paniculate, the calcification beginning near the central axis and often extending 

 into the extra-peripheral mucus as mostly isolated flocculent granules, the sur- 

 face in dry state pulverulent, farinaceous, or sometimes minutely alveolate; 

 branches for the most part progressively shorter, varying from rather sparse to 

 moderately crowded, tapering slightly to obtuse or subacute apex, 0.32-0.6 mm. 

 broad towards apex (not including hairs) ; central axis in basal parts 0.7-1.25 

 mm. in diameter, lightly calcified, often denudate, in ultimate branches mostly 



