(130 ) 
Lithothamnion fruticulosum aemulans var. nov. 
Forming an irregularly nodulose crust 10-15 mm. thick, branches 
2-5 mm. long, 1.5-3.0 mm. in diameter, tuberculate, muc 
ei pugoccen hypothallic cells subquadrate, mostly 14-20 4 x 
Bs perithallic cells usually subquadrate, 6-10 » in diameter or 
vertically elongated, up ae 15 wlong: ures of men ae 400— 
© # in diameter when seen from abov (PLATE 81, 2.) 
Porto Rico: San ae near mene mark (zo. 2237). The 
single specimen seen formed a free-lying nodule or pebble ro cm. 
long and 3.5-4.5 cm. in diameter; the plant surrounds and entirely 
encloses a flattened coral axis, the two shorter diameters of which 
measure about 8 and 16 mm. The primary crust and the suc- 
ceeding branches are so much anastomosed and overgrown that 
the basal portions to a height of 6-10 mm. look almost solid, with 
numerous small lacunae, however. The cells of various strata, 
especially of the overgrowing hypothallia and the cells which occupy 
the overgrown conceptacles are densely charged with amylum- 
bodies, which, in a gross section, appear to give an added white- 
ness to the parts in which they occur. The plant resembles in 
habit forma crasstuscula Fosl. (Bot. Tidsskrift 24: 17. 1902), 
though the conceptacles are a little smaller. It is possible that it 
represents a distinct species closely allied to Z. frutzculosum, but 
it cannot be kept separate at present. The specimen is burdened 
with foreign bodies and much water-worn. 
Goniolithon Rhizophorae sp. nov. 
Thallus forming crusts attaining a thickness of about 0.4-1. o mm. 
-in di 
height of 5-10 mm. : hypothallic cells in part aecuneene and 12— 
w in diameter and i in part elongated and then 12-30 » 5H 
perithallic cells somewhat variable, partly subquadrate or pounded 
tion: conceptacles conical, o.8-1.0 mm. in diamater when seen 
from above. (PLATE 82, F. 2.) 
Banamas: Stocking Island, Great Exuma (zo. g770), on roots 
of Rhizophora Mangle near the low-water line. 
Goniolithon Rhizophorae stands on the one hand near Goniolz- 
thon Notaristi propinguum Fosl., and on the other it is closely 
connected with Gonzolithon strictum Fos]. Specimens destitute 
of branches are difficult to separate from the former species and 
