FRESH-WATER ALG^ OF THE UNITED STATES. 169 



diameters. Fig. 5 c is an outline of a pair of fertile cells enlarged to the same 

 extent. 



Sp. parvispora, Wood. 



Sp. articulis sterilibus diametro 2-4 plo longioribus ; fructiferis baud tumidis, diametro l-2i plo 

 longioribus ; fasciis spiralibus 4, angustis, nodosis, anfr^ctibus pluribus ; zygosporis parvis- 

 simis, ellipticis, diametro l;^-2 plo longioribus ; cytiodermate utroque fine nee protenso nee 

 replicato. 



Diam.— Art. steril7|g/=.003"; spor. diam. transv. tJ^/— 7iJ/=.002"— .0023",long. ,ij/ 



30 " 



T60Ty 



Syn.—S. parvispora, Wood, Prodromus, Proc. Am. Philos. Soc. 1869, p. 139. 



Jffab. — In stagnis, Hibernia, Florida. (Wm. Canby.) 



Sterile joints 2-4 times longer than broad ; fertile not tumid, 1-2^ times longer than broad ; 

 chlorophyl bands 4, narrow, nodose ; turns many ; zygospores very small, elliptical, 1^-2 

 times longer than broad ; cell wall not infolded at the end. 



Remarks. — I am indebted to Mr. Wm. Canby for specimens of this species, 

 which he collected in a pond in the Pine Barrens near Hibernia, St. John's Eiver, 

 Florida. It is remarkable for the comparatively small size of the spores, which do 

 not nearly fill the perfectly cylindrical mother-cells ; indeed they are only about as 

 long as the latter are wide. This species closely resembles S. majuscula, but is 

 larger, does not, that I have ever seen, vary like it in the number of spores, and is 

 especially separated from it by the very small size of the latter. 



Fig. 7, pi. 15, represents a fertile pair of filaments of this species magnified 125 

 diameters. 



Sp. majuscula, Ktz. 



Sp. pallid e et sordide viridis, frtictus tempore fusceseens ; articulis sterilibus diametro (0.002'2" 

 — 0.0025") 2^-4-10 plo longioribus; cytiodermate tenui homogeneo ; fasciis 3-4— 5 (rarius 

 1), raodo subrectis longitudinalibus, modo laxissime spiralibus,. nodosis; zygosporis globosis 

 vel ovalibus. (R.) 



Syn. — Si majuscula, KtJtzinq. Rabenhokst, Flora Europ. Algarum, Sect. III. p. 244. 

 Mab. — Prope Philadelphia. ? 



Pale and sordid green, fuscescent at the time of fruiting; sterile joints 2^-4-10 times longer 

 than broad (.0022" — 0025"); cytioderm thin, homogeneous ; spiral filaments 3-4-5 (.rarely 7) 

 partly straightish and longitudinal, partly laxly spiral, nodose ; zygospores globose or oval. 



Eemarks. —Shortlj after I commenced to study the fresh-water algse, I found 

 below the city a fruiting Spirogyra, of which I preserved only a drawing, which I 

 have since identified as apparently specifically one with the European 8. majuscula, 

 it diff"ering only in not being quite so large; my measurement was ^^/ = 0.002". 

 Not having any specimens at hand, I have copied the description from the work of 

 Prof. RabenhorSt. 



Fig. 1, pi. 15, was copied from the drawing alluded to. 



Sp. nifida, (Dillw.) Link. 



Sp. csespitibus, lubricis, saturate viridibns ; articulis sterilibus post divisionem diametro sub- 

 aequalibus, ante divisionem 2-3 plo longioribus ; articulis fertilis aliis simillibus, haud tumidis ; 

 fasciis spiralibus 4(3-4 R ), modice latis, anfractibus 1-2; zygosporis ellipticis. 



22 August, 1872. 



