NOTE 
NOTE ON THE STRUCTURE OF TRIGONOCARPON OLIV AEFORME.— - 
The seed with which the present preliminary note is concerned will be spoken of 
provisionally by the name Trigonocarpon olivaeforme , familiar to palaeobotanists 
from the work of Williamson, The question of the specific relation of the petrified 
specimens under consideration to the seeds preserved as casts, will be left open 
at present. 
The structure of Trigonocarpon was first described by Hooker and Binney 
in 1855 \ and subsequently by Williamson in 1877 2 . From the works of these authors 
a good knowledge of the more general features in the anatomy of the seed has been 
obtained. Much more recently, in 1900, the late Mr. George Wild published an 
interesting paper 8 dealing chiefly with the structure of the micropylar region and 
of the outermost layers of the testa, and in 1904 4 , Prof. F. W. Oliver gave an account 
of the French petrified specimens of Trigonocarpus pusillus originally described 
by Brongniart. Our own work is entirely based on specimens from the British 
Coal-Measures, which appear to be at least specifically distinct from the French 
forms. 
In the present note, without entering further into the literature of the subject, 
we propose to give in the first place a short general account of the structure of 
the seed, and then to place on record the chief results of our own investigations, 
leaving a more detailed and illustrated description, as well as any theoretical points 
involved, for a later opportunity. Trigonocarpon olivaeforme, which is not uncommon 
in the calcareous nodules of the Lower Coal-Measures of Britain, is a large seed 
of ovate form, the body of the seed commonly measuring at least 20 mm. in length 
by 16 mm. or more in its greatest diameter. The general transverse section is 
approximately circular and radially symmetrical, so that Trigonocarpon is a typical 
member of the Radiospermeae of Prof. F. W. Oliver 5 . The micropylar region 
was of great length, fully equal to that of the body of the seed, so that a full-sized 
specimen when complete would have measured from 40 to 50 mm. from end to end. 
This is shown, for example, in a fine specimen of the complete seed (T. Parkinsoni), 
in the Hutton Collection at Newcastle 6 . 
1 On Trigonocarpons contained in nodules of Limestone. Phil. Trans., vol. cxlv, p. 149. 
2 Organization of Fossil Plants of Coal-Measures, Part VIII, Phil. Trans., vol. clxvii, p. 248. 
3 On Trigonocarpon olivaeforme, Trans. Manchester Geological Society, Part XV, vol. xxvi. 
4 On two Palaeozoic Seeds, Trigonocarpus and Poly lophosper mum, New Phytologist, vol. iii, 
No. 4. 
5 Structure and Affinities of Stephanospermum , Brongniart. Trans. Linnean Soc., vol. vi 
(Botany), 1904. 
6 Figured in Lindley and Hutton, Fossil Flora, PI. 87, Fig. 3; Photograph in Scott, Wilde 
Lecture, On the Early History of Seed-bearing Plants, Memoirs and Proceedings Manchester 
Literary and Philosophical Society, vol. xlix, 1905. PI. Ill, Fig. 4. 
[Annals of Botany, Vol. XX. No. LXXYXT. January, 1906.] 
