NOTE 
A NOTE ON TRIGONOCARPUS. — The object of the present note is to draw 
attention to one or two points in the structure of a specimen of Trigonocarpus , which 
has been lately brought to light on cutting sections of one of the blocks in the Binney 
Collection, Sedgwick Museum, Cambridge. This block formed part of a c coal-ball , 
but the locality from which it came is unknown. 
It is not improbable that it was derived from the same 
source as the seeds of Trigonocarpus described by 
Hooker and Binney, 1 which were 1 found imbedded 
in nodules of limestone, enclosed in a thin seam 
of bituminous coal not above 6 inches thick, in 
the lower part of the Lancashire coal-field \ 
Three longitudinal sections 2 of the new 
specimen of Trigonocarpus have been cut, one 
of which 3 is practically median (PI. VI, 4 Fig. 6). 
The chief interest of the specimen lies in the fact 
that the sclerenchyma of the micropylar beak is 
preserved as far as its extreme apex, this region 
being shown more completely than in any other 
longitudinal section at present known. The text- 
figure represents one side of the micropyle ; the 
sarcotesta(^.)is not complete, though it is prolonged 
for a little distance beyond the sclerotesta (sc.). 
Another point on which the present specimen 
throws some light is the question of the connexion 
of nucellus and integument. The appearance of scd= sclerotesta 
the tissues, at the level at which the nucellus leaves 
the integument, distinctly suggests that, in life, the nucellus was actually free from 
the integument almost to the base of the seed, as Scott and Maslen 5 6 are inclined 
to believe. PI. VI, 4 Fig. 7, represents the junction of nucellar wall and seed coat. 
Even if an ‘ inner flesh ' was present, there is no reason to suppose that it filled 
the entire space between nucellus and sclerotesta. An analogy may be found in the 
seed of PhyllocIadusP Here the seed-coat consists of a sclerotesta which is both clothed 
Text-fig. Trigonocarpus sp. Top 
of left-hand side of the micropyle shown 
in longitudinal section in PI. VI, 4 
Fig. 6. x 47. sa. = sarcotesta ; 
1 Hooker, J. D., and Binney, E. W. : On the Structure of certain Limestone Nodules enclosed in 
Seams of Bituminous Coal, with a description of some Trigonocarpons contained in them. PhiL 
Trans. Roy. Soc., London, vol. 145, 1855, p. 149. 
2 A.B., 10, 11, 12. Binney Collection. 
3 A.B. 11. 
4 This plate accompanies the paper by Dr. E. A. N. Arber, ‘ A Revision of the Seed Impressions 
of the British Coal Measure?,’ p. 81. 
5 Scott, D. H., and Maslen, A. J. : The Structure of the Palaeozoic Seeds, Trigonocarpus 
Parkinsoni , Brongniart, and Trigonocarpus Oliveri, sp. nov. Part I. Ann. Bot., vol. xxi, 1907, p. 89. 
6 Robertson, A. : Some Points in the Morphology of Phyllocladus alpinus , Hook. Ann. Bot., 
vol. xx, 1906, p. 261, PI. XVII, Fig. ] 1. 
[Annals of Botany, Vol. XXVIII. No. CIX. January, 1914.] 
