108 PLANTS OF RHODE ISLAND. 



DESMIDIUM, Ag. 



1. cylindricum, Grev. Common. 



Dklyinoprium Grevillei, Ktz. Alg. Rhod. No. 116. 



2. Swartzii, Ag. Common. No. 118. 



3. Baileyi, (Ralfs.) 



Aptogonium Baileyi, Ralfs. Alg. Rhod. No. 119. 



4. Aptogonium, Breb. Quidnesset. 



SPH^ROZOSMA, Corda. 



1. pulchrum, Bailey. Davisville. 



var. planum. Davisville. 



var. inflatum. Davisville. 



2. filiforme, Rab. Spectacle Pond. 



3. excavatum, Ralfs. Spectacle Pond. 



4. serratum, Bailey. Spectacle Pond, &c. 



5. pulchellum, (Arch.) var. bambusioides, Rab. Quite 



common. 



MESOT^NIUM, Naegr. 

 Endlicherianum, Naegr. Providence, &c. 



SPIROT^NIA, Breb. 



1. condensata, Breb. Providence, Mr. Lathrop, 



2. obscura, Ralf. Common. 



PENIUM, Breb. 



1. Digitus, (Ehrh.) Breb. Roger Williams Park, &c. No. 151. 



2. margaritaceum, Breb. Common. No. 150. 



3. interruptum, Breb. Providence, Mr. Lathrop. 



4. closterioides, Ralfs. Spectacle Pond, &c. 



5. truncatum, Ralfs. Davisville. 



6. minutum, Cleve. Woonasquatucket. 



7. polymorphum, Perty. Pocasset. 



8. Brebissonii, (Meuegh.) Ralfs. Quidnessett. 



9. Navicula, Breb. Common. 



CLOSTERIUM, Nitsch. 



1. juncidum, (Ralfs.) Common. 



2. macilentum, Breb. Providence, Mr. Lathrop. 



3. gracile, Breb. Providence, &c. 



4. lanceolatum, Kg.* Common. 



5. didymotocum, Corda. Providence, &c. 



6. subtile, Breb. Quidnessett. 



7. angustatum, (Kg.) Davisville, &c. 



8. Liunula, (Ehrb.) Providence, Mr} Lathrop ; Spectacle Pond. 



No. 158. [ 



var. striatum. Providence, &c. 



* A very broad form is found in Blackamore Pond. 



