REVIEW. 
Oct., 1889. 
242 
The indentations so frequent in the Triassic pebbles may, 
of course, and in fact do, survive when the disturbance of the 
beds at a later epoch has not been very great, but if we 
observe the actual beds, the correspondence of the pits on 
pebbles which are in contact prevents any mistake as to the 
age of the deposit. 
As at the beginning of these notes, so now I again call 
attention to the very fragmentary character of what I have 
brought forward. The pebbles from Cannock and Kinver 
still have to be examined, although Professor Bonney has, of 
course, worked at the former locality. In such an investi¬ 
gation, more almost than in any other petrological work, 
“ adventures are to the adventurous,” or, rather, any worker 
may, at any time, come across a new piece of information, in 
the shape of a pebble, by no merit of his own, but simply by 
the fact of its not having been bared before. 
At anv rate I have shown that there are a fine series of 
rocks to be found by anyone even in our apparently unin¬ 
teresting pebble beds. 
The British Moss Flora. Part XII. Favi. X., Grimmiacece II. Fam. XI., 
Schistostegacece. By B. Braithwaite, M.D., 303, Clapliam Hoad. 7s. 
This part, which concludes the monograph of British Grimmiacese, 
contains forty-seven pages of letterpress and seven plates, with 
descriptions and illustrations of twenty-five species and twelve 
varieties, both descriptions and illustrations being characterised by 
the exactness and finish that have been peculiar to this work through¬ 
out. In dealing with the difficult genus Orthotrichum, the author 
divides the species into two sections, by means of the stomata to be 
found upon the walls of the capsule. Sect. 1, Gyrnnoporus, includes 
those species in which the stomata are superficial, the gourd cells 
being naked and visible. Sect. 2, Calyptoporus , includes those species 
in which the stomata are immersed in the wall of the capsule, and 
more or less covered by some of the epidermal cells. These bodies, 
which are abundant on the capsules of some species, form a ready 
means for separating nearly-allied forms, and the importance of this 
new feature in the diagnosis will commend itself to all students of this 
difficult group. The excellent illustrations which are given of the 
stomata peculiar to each species will be found very useful as aids to 
determination. 
The genus Weissia, Ehrhart, follows this, and contains those 
species of the Ortliotricheae characterised by having leaves with plain 
margins, twisted when dry, and placed by the older botanists. Wilson 
and Scliimper, in the genera Orthotrichum or Ulota, but Ehrhart’s 
name, Weissia, has priority. The part concludes with a description 
and full page illustration of the pretty little Cavern Moss, Schistostega 
Osmundocea. 
This part, which is one of the most helpful and valuable portions 
of the author’s great work, completes one-half of the whole work. 
J. E. Bagnale. 
