40 Nr. 2. C. H. OSTENFELD and C. SYRACH LARSEN: 
further north in a belt, where the two species meet one 
another (CAJANDER; ibid p. 8). Similar forms probably 
occur in the extreme north near the mouth of the Jenisej, 
contradictory reports existing regarding the larch species 
in these districts. SCHEUTZ states that L. sibirica is the 
only larch near the Jenisej, also attributing the most 
northerly, stunted specimens between Dudino (Lat. 69° N.) 
and the Arctic Sea to this species (Kgl. Sv. Vet. Handl. XXII, 
No. 10, p. 41). MIDDENDORFF, who devoted special attention 
to the relation between the two larches, and endeavoured 
to fix the boundary between them during his sojourn near 
the Jenisej, came, on the other hand, to the result, that 
the dividing line between L. Gmelini and L. sibirica must 
be looked for between lat. 67'/2° and lat. 68'/2° N., and that 
only L. Gmelini at any rate was to be found at lat. 69/2" N. 
He also suggested the possibility of the existence of a 
transition belt with intermediate forms between the two 
species (1. c. pp. 530 and 595). MippENDORFF supposed 
that L. Gmelini formed the forest line as far west as about 
the spot where the Ob empties itself into the Arctic Sea 
(l. c. p. 538). His statements here are not based on personal 
observation, and L. Gmelini has never subsequently been 
found so far west; SCHEUTZ too (l.c. p. 47) only found L. 
sibirica there. The relation between the two species will be 
seen from the foregoing to be still insufficiently illuminated, 
but as already stated, it appears reasonable to suppose 
that a transitional zone lies in this district as well, and 
that in all probability the boundary lies somewhere in the 
neighbourhood of the mouth of the Jenisej. 
Eastwards, L. Gmelini is found as far as the coast bor- 
dering the Sea of Ochot, the only localities where it does 
not occur being the coast of Kamtschatka and the northern 
