238 SEWARD: A NEW BRITISH CARBONIFEROUS FOSSIL. 
Schenk does not agree with the relationship of Fayolia and 
Gyrocalamus as expressed by Weiss in his adoption of the former 
name; he refers the French Fzyolia to the attention of Ichthyo- 
logists as possibly belonging to their department of palzeontology. 
Acting on this hint from Schenk, Renault and Zeiller,* the authors 
of Fayolia, examined a number of sharks’ eggs, and were at once 
struck by the striking resemblance of the egg of Cestracion philippt 
(the Port Jackson Shark), to the Commentry species of their genus. 
There is the same pair of spirally-wound keels and collarettes, and 
the surface of the egg-membrane shows a further correspondence in 
the presence of fine striations parallel to the keels. 
In their original description of Fayolia, Renault and Zeiller 
made reference to traces of cells detected in the carbonaceous 
matter on the surface of the fossils ; but this observation, in the 
light of the new view as to the affinity of the genus, is found to have 
been founded on some accident of fossilisation. The spines and 
‘nerves’ were found arising from the circumference of the egg, and 
radiating in the membrane as if formed of fibres aggregated together 
in small bundles, and presenting an appearance somewhat similar 
to that of the spines of Fayolia. If these pencils of hairs were 
free instead of embedded in the membrane, the characters of the 
fossil spines would be more or less exactly reproduce ed. 
In one of the figures of Fayolia grandis in the monograph by 
Renault and Zeiller, two isolated helicoidal collarettes are shown, 
one wound about the other, and affording no indication of having 
been separated from the fossil by tearing. If these be regarded as 
free prolongations of the membranous collar of certain fishes’ eggs, 
such as occur in some Rays, or as spirally-coiled filaments in 
Scyllium, they at once become intelligible. 
‘We believe then,’ to quote the French authors, ‘that the Fayoltas 
are decidedly fishes’ eggs which resemble the eggs of Cestracion, the 
eggs of Rays or Scyl/ium, and the eggs of Chimera, with which they 
further agree in their spindle-shaped form, and in the thinner nature 
of their membrane.’ It is not without interest to note that M. Ch. 
Brongniart has recorded Pleuracanthus gaudryi from Commentry, 4 
fish which combines several of the characters of these different groups, 
and shows a resemblance in the form of its egg to Fayolia dentata. 
Spirangium is also compared to the eggs of fishes such as Cestracion, 
etc. Renault and Zeiller refer to some figures of fishes’ eggs which 
resemble Fayolia. ‘The greatest resemblance occurs in Cesfracion 
* Compt. rend. Vol. cvii., 1888, p. 1022. 
