an archaic type of Seed from the Palaeozoic Rocks. 75 
Memoirs. 1 More recently, the late John Butterworth called attention to the 
ribbed character and hairy covering of the seed, and published photographs 
of a tangential longitudinal, and of an oblique transverse section. 2 These 
photographs are sufficient to establish the identity of Williamson’s Sporo - 
carpon ornatum and Physostoma . 3 
II. Organization of the Seed. 
1. General Features. 
Physostoma elegans is a small seed showing considerable resemblance 
to the Lagenostomas in the general features of its organization. It is a 
straight, ribbed seed, with a free integument in the apical region ; its length 
from the chalaza to the tip of the multipartite integument reaches 5J-6 mm. 
— or occasionally a trifle more when the arms are fully extended. In trans- 
verse section it is circular, the longitudinal ribs, usually ten in number, 
giving the outer surface of the testa a sinuous contour. The seed is 
broadest about one-third up from the base, where its diameter (excluding 
the hairs which adorn the ribs) just exceeds two millims. The seed is thus 
a narrow one, broadest somewhat below the middle, and tapering gently 
towards the apex (Text-fig. 1). At the base it is bluntly rounded, so that 
a median longitudinal section recalls a cuttlefish in miniature. 
The central body or nucellus of the seed, which has a length about 
five-sixths the entire seed, ends in a large apical pollen-chamber. The 
longitudinally ribbed integument is coalescent with the central body for 
a distance of about four millims. from the seed-base. Just below the pollen- 
chamber the integument, as a whole, becomes free from the central nucellar 
body, as in the Lagenostomas, and at once breaks up into about ten arms or 
tentacles to form a whorl or circlet which loosely surrounds the pollen- 
chamber. The free arms are the direct prolongation of the convex ribs of 
the testa, or, stated in a slightly different way, the testa forms a ribbed 
envelope coalescent with the body of the seed throughout its lower two- 
thirds, but free above where the ribs part to form the tentacles. 
This replacement of the usual micropylar tube of the integument by 
separate arms is a distinctive character, in which this seed differs from all 
other known seeds, fossil or recent. These relations will be understood 
from a glance at the diagrammatic representations of a longitudinal section 
in Text-fig. 1, taken in conjunction with the series of transverse sections 
1 Phil. Trans., 1880, p. 510, and PL XVIII, Fig. 39; Ibid. 1883, p. 469, and PI. XXXI, Fig. 
27. In the latter the name is inadvertently cited as Sporo carpon anomalum in the description of the 
figures on p. 474. 
2 J. Butterworth, Some further investigation of Fossil Seeds of the genus Lageno stoma. Mem. 
and Proc. of the Manchester Lit. and Phil. Soc., vol. xli, pt. iii (1897). 
3 This identification received independent corroboration in a note in the New Phytologist, vol. 
ii, p, 18 (1903). 
