60 PROCEEDINGS: BOSTON SOCIETY NATURAL HISTORY. 
P. bupleuroides Fernald. Common in brackish ponds. J. Ma- 
coun (C. no. 22,081); H. T. Giissow (E); //. Ht. 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. ./. 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. 
Mcwoun (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. Macoim'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. ./. Dwight, Jr., (D. pp. 1.3 & 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. Giissow. H. St. John, 
no. 1,128 (H). 
