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is identical in the three genera, though in Jdenburgia they are larger and 
more massive in size and appearance. 
Dr. Rendle kindly examined the pollen, which is tetrahedral in shape, 
offering no points of interest or comparison. 
The unilocular ovary of Trimenia and Piptocalya is identical in structure 
with the bilocular Jdenburgia. This organ is somewhat flattened in one 
plane, showing angulation according to the pressure and number of the 
inner whorl of stamens, or in J. arfakensis the one whorl of stamens. The 
peculiar massive, sessile stigma is also identical, but the shape is masked 
in the first two genera by the outgrowth of papilla. In Trimenia, however, 
in the younger stages, the lines formed by the pressure of the stamens 
before the outgrowth of the papillae show the similarity of structure with 
that of Idenburgia. 
The anatomical characters agree with those given in Perkins and Gilg’s 
Monograph of the Monimiaceze. The wood in all three genera is soft 
and pithy. In the three species of Trimenia which I have been able to 
compare with Jdenburgia there is absolute conformity. The primary cortex 
is characterized by stone cells, united in groups, though in J. arfakensis 
these show a more or less continuous ring; balsam cells, with contents 
soluble in alcohol, are scattered through the bast. The xylem is composed 
of radial rows of often chambered vessels of considerable size, with 1—4-celled 
medullary rays, and is succeeded by a large medulla of parenchymatous cells 
without contents. In J. arfakensis the vessels of the wood are much smaller. 
There is the same agreement in the structure of the leaves so far as 
Trimenia and Puseaiie are concerned ; but in Idenburgia we get a 
difference between the two species, viz., the small alternately disposed 
coriaceous leaves of J. novo-guineensis show a very small-celled epidermis 
without stomata, no hypoderm, then a regular two-layered palisade-tissue, 
the lower row of much smaller cells, succeeded by a loose-celled spongy 
parenchyma and a small-celled epidermis, which alone shows stomata. The 
much larger quasi-membranous leaves of J. arfakensis agree in structure 
with those of Trimenia and Piptocalyx, as given in the Monograph and 
examined by myself, viz., a small-celled epidermis, without stomata, no 
palisade-tissue or hypoderm, but a very loose-celled mesophyll interspersed 
with large secretory cells and showing stomata on the lower epidermis only. 
Balsam, soluble in alcohol, is distributed equally through all the tissues 
of leaf and stem in J. novo-guineensis, giving the a red colouring 
which recalled Drimys in the field. 
This genus is named in honour of Mr. A. W. F. Idenburg, lately Governor- 
General of the Netherlands Indies, to whom I am indebted for the many 
facilities which his great courtesy and interest in the scientific scope of the 
proposed work most generously assured me while in Dutch N.W. New 
Guinea, 
