130 Salmon . — A Monograph of 
tropical America ; in a few instances they are apparently 
identical, but for the most part they are rather cognate 
forms.’ Baron, also, in his ‘Flora of Madagascar’ (Journ. 
Linn. Soc., xxv, 289: 1889) has pointed out the close 
affinity of certain plants in the phanerogamic Flora of 
Madagascar with those of tropical America. The same 
distribution is found in. certain ferns (see Baker in Journ. 
Linn. Soc., xvi, 199: 1877),. and there is a species of 
Lycopodium , L . dichotomum , Jacq., which is peculiar to 
Madagascar and tropical America. 
Three other species of Streptopogon — 5 . calymperoides , 
C. Mlill., from Costa Rica, S. Schenckii , C. Mull., from Brasil, 
and S'. Calymperopsis, C. Mlill., from Bolivia — have also been 
published. Of these ‘ S. Schenckii ’ alone has been published 
with a description. In the diagnosis the characters given are 
those found in S. rigidus , and an examination of examples of 
( S. SchenckiV from Muller’s herbarium and in the Kew 
Herbarium has convinced me that the plant is not distinct 
from S. rigidus. It is a somewhat luxuriant form of the 
species, with the upper leaves long and laxly incurved in the 
dry state, and bearing at their apex globose heads of gemmae. 
A still more luxuriant form, but obviously the same species, 
occurs in the Kew and British Museum herbaria, and in 
Mitten’s herbarium, labelled ‘ 5 . rigidus , Andes Bogotenses, 
J. Weir, Musci Novae- Granatenses, nr. 369,’ and also in 
Mitten’s herbarium from ‘ Tunguragua (Spruce).’ In this the 
upper and terminal leaves are strongly flexuoso-incurved when 
dry, and about 5 mill. long. It may be noted that in the 
diagnosis of 5 . Schenckii the leaves are described as ‘ limbata, 
limbo indistincto, ab unica serie cellularum subquadratarum 
vel breviter rectangularium minorum formato.’ It is certainly 
the fact that the cells towards the margin of the leaf of 
N. rigidus are different in shape from those elsewhere, but it 
seems to me that the change in shape takes place too gradu- 
ally to allow us to speak of the leaf as being ‘ limbate.’ The 
cells in the upper half of the leaf vary in shape from more 
or less regularly hexagonal to hexagono-rectangular or even 
