296 Slapf — On the Sonerileae of Asia. 
land near Quop in Sarawak, and in a form which is absolutely 
identical with that which was described by Thwaites as S'. 
pumila. 
2. S. Brunonis,W. et Arn. Central Ceylon ; Tinnevelly Distr. 
3. S. wightiana , Arn. (Syn. S. wightiana , sensu strictiore ; 
S. arnottiana , Thw. ; S. tomentella , Thw. ; S. hookeriana , Arn.) 
Central Ceylon ; Western Peninsula, northwards as far as the 
Anamally Hills. 
Whilst the formation of hairs is either entirely suppressed 
or limited to a few small scattered bristles on the leaves in 
S. zeylanica , it assumes a far more intensive development in 
a very closely allied set which otherwise differs but very little. 
The difference is indeed so trifling that further investigation 
on the spot may prove the existence of an uninterrupted con- 
nexion between this hairy set and that of .S', zeylanica. The 
former, which I comprise under the name of .S'. wightiana , 
Arn., is closely linked to .S'. zeylanica by a form which was called 
A. tomentella by Thwaites, and only differs by the almost 
tomentose covering on the stem, the petioles along the 
nerves on the back of the leaves, on the pedicels and on the 
calyx. But whilst there is — at least as far as our knowledge 
goes at present — a distinct though slight gap between .S'. 
tomentella and 5 . zeylanica , the former runs completely away 
into a still more tomentose form, with more robust habit and 
a stem more or less woody at the base, .S', wightiana , Arn., 
and passing this stage arrives finally at the extreme develop- 
ment of trichomes in .S', hookeriana , Arn. 5 . tomentella was 
collected in the Saffragam District (Thwaites, C.P. 2616), 
A. wightiana and .S', hookeriana both on Adam’s Peak 
(Thwaites, C.P. 3907 ; resp. 426, 173), all within the area 
of A. zeylanica. From the same locality, Adam’s Peak, 
another species was described as 5 . arnottiana by Thwaites. 
The type-specimens of it are represented on three sheets in 
the Kew Herbarium (Thwaites, C.P. 2615). They are iden- 
tical with those of .S', tomentella. These specimens vary 
remarkably in the thickness of the tomentum, and one or 
two plants are almost glabrescent. These forms, however 
