Characeae. 41 
Braun described a number of forms (some of them originally as species) 
with which we have endeavoured as far as possible to identify the West In» 
dian specimens.. We do not however regard these as distinet varieties but 
rather as stages of variation between which series of intermediates are to be 
found. Dr. Auen described several of the forms as species but we under- 
stand subsequently followed Braun in concluding that they all belonged to 
the one species. Mr. ©. B. Ropıwson in Bull. New York Bot. Gard. IV 
(1906) p. 282— 295 has kept up Braun’s and Aruen’s species and has 
added to the number. Nearly all the specimens we have examined appear 
to be more or less intermediate rarely agreeing exactly with any of the 
named forms. 
1. forma elegans. — C. gymnopus var. elegans T. F. Allen Oharae. 
amer. (1879) part 1 t.1; Braun Fragmente (1882) p.189. — 0. ele- 
gans Robinson l.c. p. 283. 
Plant rather large, but slender. Branchlets 11—13, with 7—10 
segments, the last 1—4 ecorticate. Bract-cells 8-9 spreading whorled, 
the posterior but little shorter than the anterior. Oogonia produced 
at the first node. 
2. forma triehacantha. — C. gymnopus var. trichacantha Braun 
Fragmente (1882) p. 190. — C. triehacantha Robinson l.e. p. 294. 
Plant rather large and slender. Branchlets 12—13 with 10—15 
segments of which the first and last are ecorticate. Spine-cells and 
anterior bract-cells long and slender, posterior bract-cells at lowest 
node much shorter and sometimes ventricose and inflexed. Oogonia 
produced at the first node. 
3. forma fertilissima. — C. gymnopus var. fertilissima Braun 
Fragmente (1882) p. 192. — 0. fertilissima Robinson l.e. p. 286. 
Plant small slender. Branchlets 12—13 with 9— 10 segments, 
the last 1—3 ecorticate. Anterior 2 pairs of bract-cells longer than 
the oogonium, next pair shorter, posterior usually quite short. Oogonia 
almost cylindrical produced at the first node. 
4. forma ineonstans. — C. inconstans Kuetz. Tab. Phye. (1857) 
VI 1.28 1.70 f.2.— C Oerstediana et Oruegeriana Braun Monatsb. 
Berl. Akad. 1858 p. 367—8. — Ü. gymnopus var. inconstans Braun 
Fragmente (1882) p. 193. 
Plant rather small, weak. Branchlets about 11, with 7—10 
segments, the lowest not shortened as in the other forms (except 
sometimes in form 9), the following 1—3 usually corticate, sometimes 
all ecorticate. Anterior pair or two pairs of bract-cells longer than 
the oogonium, others shorter. Oogonia produced at the lowest node. 
5. forma Berteroi. — C. indica Bertero in Spreng. Syst. Veg. IV 
(1827) p. 346. — 0. polyphylla var. guadeloupensis Braun in Boston 
Journ. Nat. Hist. vol. V (1845) p. 264. — C. polyphylla vars. Berteroi 
