138 
collectors in our Western States to this fact; to give in each case 
the exact localities where the types were collected, and to solicit 
* more material, in order to enable us to arrive at some Satisfactory 
conclusion in the future. To facilitate the better understanding 
of these species, they have been divided into groups, 5 with super- 
ficial stomata and 7 with immersed. Some of the species are 
referred with some doubt to these groups, and will. probably have 
to be transferred when better understood. We have to thank Dr. 
Venturi for his valuable assistance, and M. J. Cardot and Prof. 
Macoun for the receipt of portions of types from their herbaria. 
SecTIon A. Those with superficial stomata. be 
I. Group OF ORTHOTRICHUM RUPESTRE, 
This is entirely a Western group, none of the members of t 2 
having been collected east of the Rocky Mountains and Texas. 3 
To this group belong five species and several varieties, enumerated 
below. Rock species with short immersed capsules, with 8 distinct 
ridges, 16 erect teeth and 8 cilia. Calyptra hairy. = 
1. ORTHOTRICHUM RUPESTRE Schleich. Crypt. Helv. Ex. No. 24 
(1806). ee 
This species needs further study. Mr. Leiberg says that he 
meets with very puzzling variations, and his collections show 4 
great diversity of forms, all within certain well-defined limits, how” 
ever. As there have been five European varieties described by 
Venturi, only one of which is reported as American, it would 
seem as if critical work on this species would repay study. A oa 
cent paper in the Revue Bryologique, 58 (1893), states that this 
species, as well as O. Sturmii in Europe, has a preperistome be = 
the other group of rock species with immersed stomata. r 
Type specimen European. American specimens S0 name? 
are distributed from the Rocky Mountains west to the Pact 4 
Coast. Reported from California, Oregon, Nevada, Idaho an© 
Colorado. Hae 
2. OrTHOTRICHUM StuRMU Hoppe and Hornsch. Regensb. Fl ah 
89 (1819). Sull. Mosses U.S. 33 (1856), L. & J. Man- 166 
(1884). ee 
This species is very close to the above, and is separable from 
__ it only by its denser bistromatic leaves and the abrupt base 
