1905] Evans,— Notes on New England Hepaticae, — III 57 
slender hair-like spur, about four cells long and one or two cells 
wide at the base. According to Gottsche! this spur represents the 
true apex of the lobule. If the conditions for growth are unfavor- 
able the lobule often fails to develop a water-sac and then consists 
of a small pointed lamina, which is sometimes so reduced as to be 
scarcely apparent. The underleaves are bifid, with slender acumi- 
nate divisions, and are either entire on the margins or bear one or 
two lateral hair-like teeth. 
In /. pennsylvanica the leaves vary from rounded or obtuse at the 
apex to apiculate, the apical tooth being rarely more than two or 
three cells long; the margin is otherwise entire. The lobule is 
invariably without a spur and is often slightly narrowed at the 
mouth. The divisions of the underleaves are sometimes blunt but 
are usually acuminate, and the margins, in rare instances, are angu- 
lar-dentate on the sides; as a rule, however, the margins are quite 
entire. 
The differences noted in the leaves also appear in the bracts, 
although possibly in a less degree. In both species the bracts are 
deeply and subequally bifid. In 7. Hutchinsiae the lobe is ovate and 
long-acuminate, and there are several spine-like teeth on the margin; 
the lobule is also acuminate but is commonly entire. In J. pennsyl- 
vanica both lobe and lobule are broader than in the other species and 
are abruptly apiculate or acuminate at the apex; the margins are 
entire. The bracteoles in both species are deeply bifid with acu- 
minate divisions, but those of 7. Hutchinsiae taper more gradually 
and usually bear a few spinose teeth on the margin, instead of being 
entire. 
Lindberg’s variety ¿ntegrifolía, based primarily on Irish specimens, 
is not wholly destitute of teeth. It seems to be little more than an 
attenuate and poorly developed form of 7. Hutchinsiae, and is so 
regarded by Pearson and other European writers. The specimens 
figured by Moore? are practically without lobules and present a very 
different appearance from robust and well-developed forms of 7. 
pennsylvanica. 
In the opinion of the writer /. pennsylvanica represents a distinct 
species with a definite geographical distribution. The entire leaves 
and the lobules without spurs afford reliable differential characters. 
1G. & R. Hep. Europ. 477 (note). 
? Proc. Roy. Irish Acad. II. 2: 7. 45. 1877. 
