ISO ARBER : FOSSIL FLORA OF SOUTH YORKSHIRE COALFIELD. 
Trigonocarptis Sip. 
Plate XVIII., Fig. 1, Plate XIX., Fig. 3. 
1899. Trigonocarpus sp.. Arber, Fossil Plants, Fig. on p. 42. 
The two halves of a nodule, containing a fine specimen showing 
the external surface of a seed of Trigonocarpus, are figured on 
Plate XVIII., Fig. 1*, and Plate XIX., Fig, 3. The broad, wing- 
like portion is formed by the fleshy seed-coat or sarcotesta, the 
oval, central portion is the hard seed-coat or sclerotesta, of the 
body of the seed, which is prolonged upwards as a long micro- 
pylar tube^. . , 
Impressions of the external surface of Trigonocarpus are rare 
as compared with casts of the seed cavity, such as Trigonocarpus 
parkinsoni Brong., and T. noeggerathi, Sternb. The external 
surface of the seed, whose internal cast is known as T. parkinsoni 
Brongn., is probably that first figured by Lindley and Hutton^ 
under the name Carpolithes alata, of which excellent examples 
have also recently been figured by Scott and Maslen'*^. As com- 
pared with this species, the present specimen appears to be much 
shorter in proportion to its breadth, the micropyle being shorter 
and the seed broadly oval in form, rather than elongately elliptical. 
It is probably distinct specifically from Carpolithes alata, and 
perhaps T. noeggerathi, Sternb. may have been the corresponding 
internal cast of the seed cavity, though of this there is no evidence 
at present. This type of seed has, however, been found from the 
Upper Coal Measures, where T, noeggerathi occurs, but not 
T. parkinsoni. For the present, however, it does not seem ad- 
visable to suggest a new specific name for what is probably only 
a rare state of preservation of a common fossil. 
Sphenopteris {Corynepteris) coralloides, Gut bier. 
Plate XVIII., Fig. 3, Plate XIX., Fig. 2. 
1835. Sphenopteris coralloides, Gutbier, Abdriicke Verstein., 
Zwickau. Schwarzkohl., p. 40, Plate V., Figs. 8, 8a. 
One half of this specimen was figured in my " Fossil Plants," Gowan's Nature Series No. 21, 
p. 42. 
1 For the structure of this type of seed, see Scott and Maslen (07). 
2 Lindley & Hutton (31). Vol. II. PI. 87, Fig. 2 and 3, Vol. III. PI. 210. Fig. B. 
3 Scott & Maslen, (07), PI. XII., Fig. 16 and 17, PI. XIII., Fig. 18. 
