60 PROCEEDINGS: BOSTON SOCIETY NATURAL HISTORY. 



P. bupleuroides Fernald. Common in brackish ponds. J. Ma- 

 coun (C. no. 22,081); H. T. Gussow (E); H. St. John, no. 1,124 (H). 

 Fr. August and September. 



[P. PERFOLIATUS L. The specimens from Sable Island interpreted 

 as this prove to be the American P. bupleuroides.] 



[P. FRIESII Rupr. J. Macoun's collection (C. no. 22,097) proves 

 to be P. pusillus, var. capitatus.] 



P. pusillus L., var. capitatus Benn. Abundant in the brackish 

 ponds. The type collection was made in pools, July 27, 1899, J. 

 Macoun (C. no. 22,096 and 22,097); H. St. John, no. 1,125 (H). 



FL, Fr. July and August. 



[P. STURROCKII Benn. In Fryer's Potamogetons of the British 

 Isles, 85 (1915) Arthur Bennett records this plant from Sable Island.] 



P. pectinatus L. Common in the brackish pools. J. Macoun 

 (C. nos. 22,071 and 22,072); H. St. John, no. 1,126 (H). 

 FL, Fr. August. 



[P. PECTINATUS L., f. PSEUDOMARINUS Benn. In the Journal of 

 Botany, xxxix. 199 (1901) Bennett makes the combination and 

 credits the plant to Sable Island.] 



[P. FILIFORMIS Pers. The collection by J. Macoun called this, is 

 P. pectinatus.] 



[RUPPIA MARITIMA L. J. Macoun's collection so named proves 

 to be var. longipes.] 



Ruppia maritima L., var. longipes Hagstrom. Abundant in 

 Wallace Lake and the brackish ponds. J. Macoun (C. no. 22,635) ; 

 H. St. John, no. 1,127 (H). 



FL, Fr. August. 



Zostera marina L. Common in Wallace Lake and washed up 

 on the sea beaches. J. Dwight, Jr., (D. pp. 13 & 40) mentions 

 that it "abounds in the lagoon, and occurs as drift along its shores" 

 and that the nest of the Ipswich Sparrow may be partly made of 

 "eel-grass. " Listed by J. Macoun; and H. T. Gussow. H. St. John, 

 no. 1,128 (H). 



