190 
atum (Schleich.) Br. & Sch., may be said also to be correctly — 
understood, though from the localities cited it is probable that two 
species are included in the description. The sixth, P. turdinaium — : 
Miiller, is a duplication of names not intended by Miiller, and 
should replace P. pyriforme for the American forms of this variable 
species. 
Since the publication of the Manual, three other species have 
been described from Macoun’s collections by Kindberg, P. megalo- 
carpum, P. strangulatum, and P. platyphyllum. The first will 
stand for the large Western forms of what we have been calling 
' P. pyriforme, the second is a synonym of P. turbinatum, and is 
third is described from such very immature specimens that it will 
also probably not stand, though Prof. Macoun and Mr. Fletcher 
owe it to students to follow this species up, and collect, if possible, _ 
more and better specimens. = 
Five other well-defined species are described and figured in thie 
contribution, and more specimens from the West and South are — 
desired. 
PHYSCOMITRIUM IMMERSUM Sull. in A. Gray, Man. Ed. 2, OF 
(1856); Icones, 93, ¢ 56 (1864). = 
P. sphericum var? Sull. Musci. Alleghen. No. 196. (1848). S 
This species is the only one of the genus which matures beat 
capsules in the fall, and is liable to be mistaken for Aphanorhegma 
serrata, which it closely resembles. The Manual says it “ differs 
merely in the inflorescence, the dehiscence of the lid, and - 
leaves more distinctly serrate by yellowish cells.” The splitting © 
the capsule exactly in the middle and the thickening of the angl 
of its cells sufficiently distinguish Aphanorhegma, whereas - 
annulus and border of 2~3 rows of denser transversely elongate e 
cells of the capsule in P. zmmersum shows its alliance’ with the 
genus to which it has been referred. : 
It has 
Type locality: « River banks, Southern Ohio, Lea.” ; 
also been collected in Western Pennsylvania, by Lesquer ee ae 
the banks of the Allegheny river, by D. A. Burnett; of the . eet 
quehanna, by J. K. Small; along the Delaware at Camden ditch 
Philadelphia, by T. P. James and C. F. Austin; along tidal ol 
banks at Wilmington, Delaware, by A. Commons; at “27. 
New York, by C. H. Peck; on sandy clay bank of the Mis 4 
ippi river, at Winona, Minn., by J. M. Holzinger; ina dry 
