190 Rhodora [OCTOBER 
endiviaefolia (Dicks.) Dumort. ‘The original Jungermannia endiviae- 
folia of Dickson (Pl. Crypt. Brit. 4: 19. 1801) was apparently based 
on an old figure of Vaillant, and there is so much uncertainty about it 
that most of the recent European writers have given it up in favor of 
the later name of Raddi, about which there seems to be no doubt. 
In the Bryologist for May, 1905, Grout refers his specimens with some 
hesitation to Р. Neesiana (Gottsche) Limpr. Since they are entirely 
destitute of mature capsules their determination is beset with difficul- 
ties and we are obliged to rely on characters derived from the thallus. 
Fortunately the internal cells of the median region afford structural 
differences which are available even in sterile material. In P. Nee- 
siana, as well as in P. epiphylla (L.) Corda, many of these cells show 
vertical bands of thickening in their walls, and these bands are often 
pigmented with purple or red. ‘They can be most easily demonstrated 
by cutting longitudinal sections through the thallus, although they are 
sometimes seen almost as clearly in transverse section. In P. Fabro- 
niana bands of this character are not developed, the cells of the thallus 
being everywhere thin-walled. Since Grout's specimens are also 
destitute of these bands they are here referred to P. Fabroniana instead 
of to P. Neesiana. Comparatively few of the publications relating to 
Pellia make use of these bands in distinguishing the species, although 
attention was called to them many years ago by Leitgeb.! С. Müller? 
however, emphasizes their importance and gives an excellent figure 
of them as they appear in P. epiphylla. 
4. Pera NEEsIANA (Gottsche) Limpr.; Cohn, Krypt.-Flora von 
Schlesien 1: 329. 1876.  Pellia epiphylla, forma Neesiana Gottsche, 
Hedwigia 6: 69. 1867. On wet rocks; Wintergreen Falls, Hamden, 
Connecticut (4. W. E.). The species is probably widely distributed 
in New England but is easily confused with P. epiphylla. All three 
species of the genus are common in Europe and Asia. "The striking 
difference in the structure of the thallus, which separates P. Neesiana 
from P. Fabroniana, is supplemented by still more striking differences 
in the structure of the capsule. In P. Neesiana the cells forming the 
inner layer of the capsule-wall develop local wall-thickenings in the 
form of incomplete rings; the elater-bearers at the base of the capsule 
are 15-25 и in diameter and number from 20 to 30; while the elaters 
1 Unters. über Lebermoose 3: 53 (footnote). 1877. 
? Rabenhorst's Kryptogamen-Flora 6: 9. f. 2. 1906. 
