Two Fossil Prothalli. 
30 7 
hearing the name of Calymmatotheca, found in the form of impres¬ 
sions, has been identified as the rachis upon which these seeds 
were produced. 1 Despite the absence, even to the present day, 
of any specimen showing absolute continuity between this female 
fructification, and the vegetative stem of Lyginodendron, the 
evidences of resemblance are sufficiently strong to preclude any 
serious doubt that the attribution of the seed upheld by Oliver and 
Scott is correct. Lagenostoma Lowaxii was the first seed recog¬ 
nized as being borne upon a fern-like plant. Being itself so fully 
known, and belonging to a plant also very fully investigated, it may 
be considered the most outstanding type of Pteridospermic seed. 
The additional specimen which it is proposed now to describe, 
emanates from Mr. James Lomax, from whom came also the 
original specimens of the seed. Found at Dulesgate, it came to 
light only after the publication of the well-known memoir in which 
all the other sections were described. Enough interest, however, 
attaches to it, to render a separate notice desirable, as it displays 
in excellent preservation a structure hitherto unrecorded. 
The section (R. 17b Univ. Coll. Colin.), is transverse, being 
the second of a series of two, cut through the lower half of a single, 
full-grown seed. The other, the companion section (R. 17a), cuts 
through the chalazal cushion and the median vascular bundle 
belonging to it, passing out below the junction of chalazal cushion 
and testa. A fine section of a pedicel of Lagenostoma is also 
included in this slide. R. 17b is approximately 1 mm. higher up the 
seed, that is to say it falls within the lower third, and well below 
the equatorial line. Neither section is absolutely transverse,— 
R. 17a being inclined about 20°, and R. 17b about 10° to the 
horizontal. 
The section R. 17a is not specially noteworthy. It strongly 
resembles R. 8a (PI. 5, fig. 13, O. and S.), and is only mentioned in 
this connection as enabling the position of R. 17b to be ascertained. 
Oliver and Scott describe as typical a shrunken appearance 
of the internal organs, the megaspore membrane being found in the 
centre, much crumpled, and closely surrounded by the “inter¬ 
mediate sack,” a shrivelled layer representing the nucellus, and a 
portion of the hypoderm, the “ bundle ring,” in which the nine 
vascular bundles are embedded, this being separated from the 
testa by a wide space called the “ outer sack.” Such is the 
appearance shown in their PI. 7, fig. 2. In the present specimen, 
1 F, W. Oliver, Farnsanten. 
