76 College of Forestry 
The Gonobasts varies greatly in width of shell. On the 
shore, back of the Water Willow association, numerous piles 
of empty, clean shells attest the presence of that good clam 
collector, the muskrat. Seven species were noted. A count 
of two related species revealed an interesting relative abund- 
ance of the two sexes. This is shown below. 
Lampsilis radiata, male, 66 per 
cent; female, 34 per cent. 
Lampsilis boredlis, male, 20 per 
cent; female, 80 per cent. 
Sration XXXI. Frencuman Istanp, Sout Sipe. 
For a distance of a third of a mile southeast of the island 
a shallow terrace extends, which ranges from 1 to 4 feet in 
depth. On the edges of this area the water abruptly drops 
to 6 and 8 feet in depth. The two islands, Frenchman and 
Dunham, are joined by a submerged ridge which is not deeper 
than 4 feet, near the latter island. 
The vegetation bordering Frenchman Island is abundant 
and varied and the station is divisible into several habitats. 
The arrangement of the vegetation is also zonal. 
Habitat 1. East of Typha Association. Fig. 24. 
Zone A. The Shore. 
Buttonbush 
dentalis). 
Buttonbush-Loosestrife Association. 
(Cephalanthus occi- Swamp Loosestrife (Decodon verti- 
cellatus) . 
Sedge (Carex trichocarpa). 
Zone B. Burreed-Arrowhead-Nymphaea Association. 
Bortom: Sandy-silt, rather soft. WatTrer: 12-24 
inches deep. 
Bur-reed (Spraganium ewrycar- Pickerel-weed  (Pontederia  cor- 
pum). data). ; 
Broad-leaved Arrowhead (Sagit- Sweet-scented Water Lily (Cas- 
taria latifolia). 
American Bulrush (Scirpus ameri- 
canus). 
talia odorata). 
Cow Lily (Nymphwa advena). 
