150 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 12 



branchlets which are simple or very sparingly alternately branched, 0.75- 

 1.30 mm long, 75-100 /* diam. near the base and markedly tapered toward 

 the tips; axes wiry, about 0.75 mm diam., corticated irregularly, in section 

 showing one large thick-walled axial cell about 180 /x diam., lying in a 

 considerable cavity which had 5-7 small filaments appressed to the outer 

 wall; cavity surrounded by 3-4 layers of moderately large firm-walled 

 cells and externally a one-layered cortex of chromatophore-bearing cells ; 

 gland cells not noticeable on the branchlets ; reproduction unknown. 



Named for Professor Nils Svedelius in recognition of his cytological 

 studies made in this family of algae. 



Ecuador: Archipielago de Colon, rare as dredged from 55 meters' 

 depth off Post Office Bay, I. Santa Maria, no. 34-378 (TYPE), 29 Jan. 

 1934. 



This plant differs much from A. Sanfordiana. It lacks the close ap- 

 proximation of short side branches along the main axes, so that the habit 

 is more openly bushy; the branchlets are less crowded and less plumose; 

 although slender it does not adhere to paper so closely as does A. San- 

 fordiana. It also differs from A. hamifera in its firmer texture and more 

 slender axis, as well as the absence of crozier branch tips, though these 

 structures are often absent from Atlantic specimens of A. hamifera. The 

 branchlets were more slender, and so far as could be seen in the material 

 available did not have gland cells. The depth from which it was secured, 

 55 meters, is beyond where one would expect to find the shallow-water 

 A. hamifera. 



Gelidiaceae 



Plants small to moderate in size, wiry in texture; axis ultimately of 

 numerous filaments though characteristically with a single cell at the 

 apex, lower down becoming corticated; asexual reproduction by tetra- 

 sporangia usually formed just below the surface of the branchlets; sexual 

 reproduction by spermatangia formed from the surface cells, and by carpo- 

 genic branches loosely associated with chains of nutritive cells; gonimo- 

 blasts intermingled with these nutritive cells and there producing the 

 carpospores. 



KEY TO GENERA 



1. Section of the plant not showing slender filaments mixed with 

 the large cells ; apical growth by a few small initial cells ; repro- 

 duction unknown Wurdemannia 



1. Section of the plant generally showing very slender refractive 

 filaments ("rhizines") mixed with the large cells which make up 

 the bulk of the central tissue 2 



