I 
.164 BULLETIX OF WISCOXSIX XATURAL HISTORY SOCIETY. VOL. 2 XO. 3. 
Asplcnium acrostichoides. 
Asplenium Trichomanes. 
Botrychium ternatum. 
Botrychium Virginianum. 
Camptosorus rhizophyllus. 
Cystopteris bulbifera. 
Cystopteris fragilis. 
The most interesting of these ferns is Dr\'opteris fragrans, on 
account of its rarity, it being known to occur in but very few and 
widely separated places. This list is by no means complete. 
7. A Tamarack Swamp in Waukesha County. 
The little hamlet of Calhoun, on the Northwestern Railway, in 
the northern part of the town of New Berlin. Waukesha County, 
lies near the eastern extremity of one of those broad depressions, 
the beds of lakes within very recent times, which are so comrnon 
in the eastern part of that county.. The drainage of this depres- 
sion, such as there is, goes towards the Fox River (of the Illi- 
nois). The width of the basin is about a mile, and the length 
from east to west about two miles. The central part of the basin 
constitutes a paludinal area, which ranges from places with open, 
shallow water and a flora dominated by Typha, through various 
grades of sedge marsh to mesophytic meadow land. The bound- 
aries of these various zones are rather indefinite and vary from 
time to time, according as there is a succession of wet or dry 
seasons. They exhibit a wealth of Cyperaceae, Gramineae and 
other grass-like forms, and will richly repay a closer study, w^hich, 
however, must be left to a future time. 
Surrounding the grass area is an irregular, much interrupted 
belt of hydrophilous shrubbery. The dominant genus in this 
association is Salix. The most conspicuous species of willow is 
a form very similar to the typical Salix sericea of the Eastern 
states. Associated are 5^. discolor, S. lucida, S. Candida, and prob- 
ablv several others, not to speak of hybrids. Mingled with the 
willows are several species of Cormis, Spiraea salicifolia, and in 
some places Vihiirnnm (especially V. Lent a go) ; and in the driest 
parts Samhucus Canadensis. Of herbaceous soecies growing in 
the shade of these shrubs, various species of Polycronuni, Inipa- 
tiens fiilva, Cardaniine rlioniboidea are among the most con- 
spicuous. 
A form of Betnla is found in these saliceta, which combines 
some of the characteristics of B. glandulosa Michx. and B.puniila 
L. Like the former its branchlets, "even the youngest, and leaves 
are entirely glabrous ; the fruit catkins are oval, or rather club- 
shaped ; it does not grow higher than about five feet, and its leaves 
