1912] Evans,— Notes on New England Hepaticae,— IX 11 
length of the cilia. In cross section a convex median region becomes 
apparent on the lower surface of the thallus, the sides rising obliquely 
and meeting the upper surface at an angle of 90 degrees or somewhat 
less. The thickness of the thallus is from one third to one half as great 
as the width. The epidermal cells are thin-walled and hyaline, the 
shape varying from broadly ellipsoidal to pyriform. They soon 
collapse and disappear, but the cells of the next layer then become 
hyaline also and apparently act as an epidermis. 
'The inflorescence is monoicous but the capsules are not always 
abundant. The spores are brown and average about 100 u in diame- 
ter. The convex face develops a regular reticulum with about eight 
meshes across the diameter, the individual meshes measuring about 
12 u in width. The ridges bounding the meshes are very low but 
sometimes project slightly at the angles as truncate or rounded papil- 
lae. Between the convex face and the three plane faces a narrow 
hyaline wing, 2-10 u wide, is formed, the margin of which is minutely 
and irregularly crenulate. The plane faces are marked with still 
lower ridges than the convex face; in most cases they scarcely anasto- 
mose, but sometimes a more definite reticulum is formed. 
Lindberg! referred R. Lescuriana as a synonym to R. Michelii 
Raddi, a species of southern Europe, which has since been described 
in detail and figured by Levier? The two species are, indeed, very 
closely related, and Müller? emphasizes the fact that the ciliate form 
of R. Lescuriana can be distinguished from R. Michelii only with 
difficulty. Apparently the median groove extends farther backward 
in R. Micheli than in R. Lescuriana, and the epidermal cells are rarely 
or never pyriform. The most important difference between the two 
species, however, is in the inflorescence, R. Michelii being dioicous 
and R. Lescuriana monoicous. Among the species of the eastern 
United States R. arvensis bears some resemblance to R. Lescuriana 
and agrees with it in having a broad median groove on the upper 
surface of the thallus. But A. arvensis is a smaller plant, more 
glaucous in appearance, and its spores are smaller and more regularly 
reticulated on the plane faces. 
6. NARDIA SCALARIS (Schrad.) S. F. Gray, Nat. Arr. British Pl. 1: 
694. 1821. Jungermannia scalaris Schrad., Syst. Samml. Krypt. 
1 Musc. Scand. 2. 1879. 
? Bull. dei'Herb. Boissier 2: 229-240. pl. 5. 1894. 
3 Rabenhorst's Kryptogamen-Flora 6: 176. 1907. 
