ALG FROM THE WEST INDIES. 271 
branches; the sheath also becomes hyaline. The cells often 
appeared like the section of a biconcave lens, owing to the con- 
traction produced by the dilute spirit in which the material was 
preserved. 
‘ 21. Scyronema FieuraTuM, Agardh. (Syst. Algar. p. 38.) 
[Secytonema calotrichoides, Kuetz. Species Algarum, p. 307; 
Tabule phycolog. ii. p. 6, t. 22. fig. ii.; Rabh. Fl. Europ. Alg. ii. 
p. 253. ] 
Crass. fil. 15°5-23 p; crass. trich. 18-13°5 p. 
Hab. On damp wall of dam, Sharp’s River, St. Vincent. 
No. 477.—On trees, summit of Trois Pitons (4500 feet), Dominica. 
Nos. 903 and 904. 
22. ScyTONEMA, sp. 
Crass. fil. 28-36 »; crass. trich. 5-5'5 p. 
Hab. Amongst §. javanicum, Bornet, on lime-trees, Shanford 
Estate, Dominica. No. 901. 
Only asmall quantity of this was seen, which was insufficient for 
accurate determination. The characters were those of S. densum, 
Bornet, and it probably is a small variety of this species. 
23. ToLypoTHRix TENUIS, Kuetz. (Phycolog. gener. p. 228; 
Tabule phycolog. ii. p. 9, t. 81. f. ii.) [T. pygmea, Awetz. 
T. flaccida, De Bary. ] 
Crass. fil. 7-7°7 4; crass. trich. 5°7 «; heterocyst. 7°7 x 5°7 p. 
Hab. On damp wall of dam, Sharp’s River, St. Vincent. 
No. 477. 
Ord. SrROSIPHONIACER. 
24. HapaLosIPHON INTRICATUS, nov. sp. (PI. XV. figs. 16-28.) 
H. cxspitibus parvis, eruginosis ; filis densissime intricatis et 
variabilibus, adultis vaginis arctis distinctis (interdum paullo 
indistinctis) e cellulis singulis formatis, sparsim ramosis ; ramis 
singulis unilateralibus flexuosis, filo primario subsimilibus, vagi- 
natis vel evaginatis ; cellulis variabilibus, diametro 12-3plo lon- 
gioribus, sepe equalibus et subrotundis, interdum elongatis : 
heterocystis intercalaribus, subquadratis vel oblongis (diametro 
1~3plo longioribus). 
Crass. fil. 4-7 » ; crass. heterocyst. 3°8-9'5 p. 
Hab. In little intricate tufts among the leaves of Leucobryum, 
on trees, summit of Trois Pitons (4500 ft.), Dominica. No. 903. 
