66 
Salisbury. — On the Structure and Relationships of 
Species. 
T. Par kins oni 
N. heterophylla 
T. Shorensis 
N. obliqua 
Length. 
4-5 cm. 
3 cm. 
Over 4 cm. 
About 6 cm. 
Breadth. 
2 cm. 
i*i-i* 4 cm. 
2*4 cm. 
2*25 cm. 
A further feature that the fructifications of N. obliqua and T. Shorensis 
have in common is found in the marked striation exhibited by the surface 
of the former, and attributed by the authors cited above to the presence of 
a large number of sclerenchymatous strands of tissue near the surface of the 
seed. These are no doubt identical with the numerous radial sclerotic 
plates which we have described as a prominent feature in the peripheral 
layers of the sarcotesta in T. Shorensis. 
In view of the occurrence of the seeds of N. obliqua in pairs on a bifur- 
cated axis, it may be of some significance that in one of our series a portion 
of a second seed is present, having approximately the same orientation as 
the more complete specimen close to which it lies. 
These considerations render it likely that our seed was itself borne on 
a plant possessing foliage of the Neuropteris type, and almost certainly 
belonged to the same subsection of the genus as Kidston and Jongman’s 
specimens. 
4. Trigonocarpus corrugatus. 
Amongst the casts of Trigonocarpean seeds, none approach so closely 
to Trigonocarpus Shorensis as that described by Renault under the name 
Trigonocarpus corrugatus. The following is the diagnosis given by that 
author : 
‘ Graines trigones, dilatees un peu au-dessus du milieu de leur hauteur, 
longues de 22 millimetres et larges dans la partie renflee de 12 millimetres, 
marquees de trois cotes saillantes qui vont jusqu’au sommet de la graine 
sans produire de point. Entre ces trois cotes on remarque trois plissements 
en relief qui s’etendent a peu pres jusqu’a mi-hauteur.’ 1 
From the above we see that the dimensions of the seed, though 
smaller than those of our own species, bear very nearly the same ratio for 
the corresponding parts of the sclerotesta. 
Species Width ( max , .) Length. Lengthfwidtk. 
T. corrugatus 12 mm. 22 mm. 1-83 
T. Shorensis 15 mm. 28 mm. i*86 
The presence of the three secondary ribs extending for only a part of 
the total length of the hard shell, though persisting for a greater distance 
than in T. Shorensis , also the absence of a beak (a description that might 
easily in this type of preservation be consistent with the presence of a very 
short structure of such a character), and the tapering base, still further 
strengthen the resemblance between the two seeds. 
1 B. Renault, Bassin houiller et permien d’Autun et d’Epinac, p. 399. 
