158 



dant in pools along the banks of the Penobscot, also in ponds 

 and springs inland. Finely in fruit. Oct. 



Several species of Spirogyra occur in abundance in Maine 

 waters, but none have yet been found by me in conjugation. 



Family XVII. — Desmidie^e. 



i6. Hyalotheca disilliens (Smith), Breb., p. 22, PL I. — Very 

 common in sheltered places along the Penobscot, and in small 

 ponds, springs and stagnant pools. 



17. Desmidmm Swartzii, Ag., p. 26, PI. II. — Common m 



shallow streams, small ponds and ditches. 



18. Sphmrozosma pulchriim, Bailey, p. 29, PL IV. — Old well 

 on college farm. The gelatinous envelope was apparent m our 

 specimens. 



19. Penium Digitus (Ehrb.), Breb., p. 34, PI. V.— Pot holes 

 at Old Town. Pool at Great Works in gathering made by Mr. 

 L. H. MerrilL 



20. P. interriiptwn, Breb., p. 35, PL V. — Both large and 

 small forms observed in gatherings made at Old Town and 

 Great Works. Not plentiful. 



21. P. Brebissonii (Menegh.), Ralfs, p. 36, PL V.— Pools 

 along the enobscot Not scarce. 



. 22. Closteriitm Ltintda, Ehrb., p. 40, PL L. — Pot hole at Old 

 Town ; also from Great Works in gatherings made by Mr. 

 MerrilL 



23. C, Cticmnis, Ehrb., p. 40, PL VL — Pools in Penobscot, 



at Old Town and elsewhere in ponds. 



the 



24. C. striolatum^ Ehrb., p. 42, PL VL — Pools near 



Penobscot at Orono. From a gathering made by Mr. Merrill 

 near Basin Mills. 



25. C. Venus, Kg., p. 44, PL VIL-Pot holes at Old Town. 



26. C Ehrenhergii, Menegh., p. 45, PL VII. — Pools near 

 the Penobscot at Great Works in gatherings made by Mr. Mer- 

 rill. Also from various small ponds about Orono. 



2J, Docidium Trabecula (Ehrb.), Na^g., p. 48, Pis. IX., XL 

 {p, Ehrenbergii, Ralfs). — Common in stagnant ponds and 

 sphagnum swamps. Orono, 



2%. Cosviarimn granatiim, Breb., p. 60, PL L. — From agath- 



