70 
T. G. HALTÆ, 
(Schwed. Südpolar-Exp. 
The present specimens agree in all respects, as far as their characters are shown, 
with such of Ptilophylliim pectmoides from the Yorkshire Oolite (Whitby, Hayburn 
Wyke, Marske and other localities belonging to the Lower Estuarine Series). Their 
resemblance to that form is, indeed, more apparent than the generic characters. It is 
fairly certain, however, that the insertion of the pinnae is the same as in Ptilophylhim 
pectmoides, and that the specimens belong to the genus Ptilophylluni. 
It is hardly possible, in regard to the great uncertainty prevailing in the classi- 
fication of Cycadean fronds, to make any statements as to the geographical or vertical 
distribution of PtilopJiylhim pectinoides. Of the many fossils which have been re- 
corded under the name Williainsonia pectai, the larger part do not belong to the 
present species, which is not known yet with certainty outside England. It occurs 
possibly in the Liassic of the Banat, Pterophyllum rigidum Andræ (1855, p. 42, 
pi. II, fig. I) being somewhat like the English species. It is possible that some few 
of the Indian Ptilophylhim fronds may be referred to this species, but it is not prob- 
able; at least all the better specimens figured by Oldham &: MORRIS and FeiSI- 
MANTEL belong to quite distinct species. The Ptilophylla from Australia come 
nearer to the Indian forms, and so do some other specimens of that genus found 
by the present writer in Patagonia. 
Genus Williainsonia Carruthers. 
Williamsonia pusilla n. sp. 
PI. 6, fig. 12. 
The small object shown in pi. 6, fig. 12, was identified by Prof. NathorST as 
a “flower” of JVilliamso/iia-type, similar to W. Fo rc ho mm eri 'Nathokst (18800). 
The specimen represents a circular cast of which the central part forms 
a semi-globular elevation. The surrounding disc is almost flat on the impression. 
The diameter of the whole object is a little more than 10 mm., that of the central 
elevation about 4 mm. On the latter there can be seen in one place, near the base, 
some faint marks of a more or less rhombic shape (not shown in the figure): other- 
wise it shows no surface-sculpture. The flat, marginal portion has a marked radial 
structure and seems to be composed of a large number of narrow radial elements. 
It is not possible to make out each individual constituent, but it is possible that 
these are free and not intergrown with each other, the appearance of continuity being 
due to a dense superposition of free appendages. 
Since the specimen is an impression, the object which made it naturally consisted 
of a rounded concave body, bearing at its brim a wide and flat collar of radially 
arranged elements. The structure cannot be well made out, but the specimen is 
