ALG^ FROM THE WEST INDIES. 271 



brandies ; 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. ScYTONEMA FiGTJEATTJM, Agardli. {Syst. Algav. p. 38.) 

 [Scytonema ealotrichoides, Kuetz. Species Algarum, p. 307 ; 

 TahulcB phijcolog. ii. p. 6, t. 22. fig. ii. ; Rahli. Fl. Europ. Alg. ii. 

 p. 253.] 



Crass, fil. 15*5-23 /x ; crass, trich. 18-13*5 /z. 



Hab. On damp wall of dam, Sharp's Eiver, St. Vincent. 

 No. 477. On trees, summit of Trois Pitons (4500 feet), Dominica. 

 Nos. 903 and 904. 



22. SCTTONEM"A, Sp. 



Crass, fil. 28-36 /u ; crass, trich. 5-5*5 /u. 



Sab. Amongst >S'. javanicum, Burnet, on lime-trees, Shanford 

 Estate, Dominica. No. 901. 



Only a small quantity of this was seen, whicb was insufficient for 

 accurate determination. The characters were those of ^S*. deiisum, 

 Bornet, and it probably is a small variety of this species. 



23. ToLTPOTERix TE>^uis, Kuetz. {Phycolog. gener. p. 228 ; 

 TahulcB phijcolog. ii. p. 9, t. 31. f. ii.) [T. pygaiaea, Kuetz. 

 T. flaccida, De Bary.'] 



Crass, fil. 7-7*7 }x ; crass, trich. 5*7 /x ; heterocyst. 77 x 5*7 fx. 

 Hah. On damp wall of dam, Sharp's Kiver, St. Vincent. 

 No. 477. 



Ord. SlROSIPHONIACE^. 



24. Hapalosipho:!^ INTEICATUS, nov. sp. (Pl.XV. figs. 16-28.) 

 II. caespitibus parvis, aeruginosis ; fills densissime intricatis eb 



yariabilibus, adultis vaginis arctis distinctis (interdum pauUo 

 indistinctis) e cellulis singulis formatis, sparsim ramosis ; ramis 

 singulis unilateralibus flexuosis, filo primario subsimilibus, vagi- 

 natis vel evaginatis ; cellulis variabilibus, diametro l|-3plo lon- 

 gioribus, ssepe sequalibus et subrotundis, interdum elongatis ; 

 heterocystis intercalaribus, subquadratis vel oblongis (diametro 

 l-3plo longioribus). 



Crass, fil. 4-7 jLi ; crass, heterocyst. 3'8-5'5/i. 



Sal. In little intricate tufts among the leaves of Leucohryim, 

 on trees, summit of Trois Pitons (4500 ft.), Domiuica. No. 903. 



