FHES11-WATKU A L U M OF TUB UNITED STATES. 211 



;/,,/,.__South Cur.ilimi; (lluvciiel) Wood. Rhode Island; (S. T. Olncy) Thwaites. 



Thullus linear, (lutti.-li, of half to a whole thumb's breadth, sometimes greatly elongate, bright 



or obscure green, dicliotoiuously subreticulately laciniato (sometimes with the habit of 



in jluitunx) ; filament and primary branches mostly colorless, sometimes coned with green, 



parallel ; lateral fu.-riculi of branches more or less dense, divaricately patent ; joints more or 



less tiimiil, (liiiiin ii-r fi|ual o'r subequal ; joints constricted ; cytioplasm effused granulate. 



L'I nntrk*. I have never seen a living or well-preserved specimen of this species, 

 and have, therefore, here simply copied the description of Prof, llabenhorst. Prof. 

 Ravenel has sent to me dried alga; labelled, and I think correctly, as belonging to 

 this species, lint their condition did not allow any scientific study of them. 



Genus PILINIA, KTZ. 



Fila artirulata, crccta, simplicia vel dichotonic ramosa, basi nffixa, in stratum criistaccum sub- 

 sponjrioMiiii, fragile aggregata. Propagatio adhuc ignota. 



Filaments articulate, erect, dichotoroonsly branched, fixed by the base, aggregated into a some- 

 what spongy fragile crnstaccous stratum. Method of propagation unknown. 



P. dilula, \Vii.in, (sp. nor.) 



1'. rupicola, in strato cano-viridi disposita ; filis ramisque fasciculatis, apice obtusis ; articulis 



diametro 1^ plo 3j plo longioribus. 

 ]>,m. Max. 0.0004". 



Hub. lu fontibus maximis, prope Bellefonte, Centre County, Pennsylvania ; Wood. 

 Growing on stones and roeks, forming a grayish-green stratum ; filaments and branches fasci- 



culate, witli the apices obtuse ; joints l-3$ times longer than broad. 



Remarks. Near Bellefonte, Centre County, Pennsylvania, there issues from the 

 linn stone rocks the largest spring I have ever seen, giving rise to a creek-like tor- 

 rent, which supplies the city with water, and passes on scarcely diminished in 

 volume. In this spring grows the curious algae under consideration, forming a 

 somewhat lubricous crustaceous and stony stratum on the stones and rocks in the 

 basin. This stratum is of a grayish-green color, and is quite friable, breaking in 

 the direction of the filaments with the greatest possible readiness. \Vhen placed 

 under the microscope it is seen to be composed of filaments whose course is a 

 direct one from the under to the upper surface. They are apparently rigid, pre- 

 serving their courses, and not being intermattcd. They are composed of cylindri- 

 cal, confervoid cells, and are dichotomously branched, and yet when viewed as 

 a whole the filament and its branches form a sort of fasciculus. The basal cell 

 ir cells appear to be globular. When I collected this plant I was forced by cir- 

 nunstances to put the specimens in carbolic-acid water for future study, and, 

 therefore, I have had no opportunity of studying their method of reproduction. 

 I am not altogether satisfied in referring this plant to the Pilinia, and yet all the 

 most important of the characters given by Rabenhorst are preserved by it. It 

 certainly, however, differs very greatly from P. rimosa, Ktz. 



Genus APHANOCHJETE, BRAUN. 



Fila distincte articulata, prostrata, repentia, interdnm in stratum irregulare plus minnsve concreta; 

 ramulig repentibus vel adscendentibus ; cellulis chlorophyllaceis, apice vel dorso setigeris. Propa- 

 gatio zoogonidiis. 



