1903] DISTRIBUTION OF ISOETES SACCHARATA 193 
at a point about 600™ northeast of Gunpowder station on the P. 
B. & W.R.R. On the small rounded point between Sugar Loaf 
Creek and Gunpowder River, I found Jsoetes saccharata on Sep- 
tember 2, 1902. The specimens were abundant but of small 
size, owing to the fact that they grew in a moderately dense 
colony of Scirpus americanus Pers., among which I have rarely 
found Isoetes elsewhere. Other associates of Isoetes at this 
station were Lilaeopsis lineata (Mx.) Greene, and Eriocaulon sep- 
tangulare With. The soil conditions were typical —gravel covered 
with a thin layer of mud. 
15. About 500™ above the mouth of Sugar Loaf Creek, on 
the east shore of Gunpowder River, I located another colony of 
Isoetes the following day, September 3, 1902. The specimens 
at this place were growing in a bed of sand only a few square 
meters in extent and were very thrifty. 
16. Havre de Grace Light is ona small point on the west shore 
of the Susquehanna River at its mouth. The most interesting 
of T. C. Palmer’s unpublished stations for Isoetes is a small area 
just north of this light house, near the pier. His collection at 
this point was made August 17, 1898, and is at present the 
northern known limit of the species. 
17. Havre de Grace Park is along the shore of the bay, south- 
west of the Havre de Grace light. It descends to the bay by a 
steep bank, and below this bank, among the pebbles which pave 
the beach, I found the species growing abundantly, July 19, 
1902. 
18. Nearly 1*™ west of the last, on the curved shore, known 
as the “knee” of the bay, Jsoetes saccharata also grows, though 
not in such abundance as at the park station. I collected at this 
place also July 19, 1902, this being my first collection. 
x. By this sign I have marked two points on Bush River at 
which single small specimens were found. The fact that these 
two specimens were seen indicates that its absence in notable 
quantity is due to unfavorable habitat, and not to barriers to its 
entrance. Although Bush River was explored from its mouth 
almost to the head of tide water, I did not see a single spot where 
I reall y expected to find it. The specimens found were evidently 
