FLORA OF THE GALAPAGOS ISLANDS. 97 
Cuatuam Ist. :. March, 1884, Marcacci, ace. to Piccone, l.c. Further 
distrib. western So. Am. 
HERPOPHYLLON, gen. prov. 
Frons membranacea, prostrata, subcircularis vel vague expansa, 
centro radicibus adfixa. Structura interne cellulis oblongis vel radia- 
tim elongatis, parietibus distincte colloideis cellulis superficiem versus 
rotundatis in stratum unicum corticale transformatis constituta. Spor- 
angia cruciatim divisa, in soris verrucaeformibus supra frondem sparsa. 
Cystocarpia ignota. 
. coalescens, spec. prov. 
Frondes circa 40 mm. diametro, aggregatae, a marginibus coalescentes, 
thallum indefinite expansum formantes. Sporangia in soris verrucae- 
formibus ad superficiem superiorem frondis inter paraphyses allata, an- 
guste ovales, 56 4 X 15-20. ALBEMARLE IsL.: Tagus Cove, March, 
1899, Snodgrass & Heller. 
The provisional name given above is adopted to designate a curious 
alga the cystocarpic fruit of which is unknown and which in other respects 
does not agree with any genus known to me. When removed from the 
fluid in which it was preserved it appeared like an irregular, rather 
cartilaginous pellicle adherent to the substratum by groups of coarse 
rhizoids. On a closer examination the surface was seen to be ridged, 
or veined, and apparently the larger specimens are composed of smaller 
individual fronds which have united, each tuft of rhizoids being in the 
centre of a frond. The smaller specimens were like the larger, but none 
seen was so small as to be composed of a single frond. The microscopic 
structure of the ridges show that they are the lines of union of two different 
fronds, or, if the whole is to be regarded as a single plant, of its different 
lobes. The internal structure consists of a compact tissue of large cells 
about 56, in transverse section but more or less elongated in radial 
sections, some being 140 long. They cannot, however, be called 
filaments. Near the upper and lower surfaces and near the margin 
the cells become more nearly spherical. The cell-walls are markedly col- 
loidal and near the margin seem to be imbeded in a solid. colloidal matrix. 
The cortical cells are small and arranged in a single layer, especially on 
the lower surface, those on the upper surface more frequently dividing 
anticlinically, especially where the sporidia are forming. The latter are 
in spots on the upper surface, which are sometimes not much raised 
but at other times form well-marked warts. The sporangia are borne 
between paraphyses about 60» long and 3p broad, formed by the out- 
VOL. XxxVirI. —7 
