Crinoidea, Pentacrininae. 
53 
a true ellipse in the following manner: the lower margin is straight and parallel to 
the suture-line; the upper margin retains the broad elliptical curve, while the suture- 
line above it rises and, as it were, cuts into the supranodal, so that the rim of 
the facet here assumes the position which between other columnars is occupied by 
the cavity; the side margins form short curves, the chords of which approach as 
they pass downwards. A strong fulcrum runs across the facet well above the centre, 
forming the chord to the upper curve of the rim ; it is swollen at its ends, which 
are quite distinct from the rim, and widens slightly around the lumen; it often has 
a slight median groove. The facet, measured from outside its rim, occupies nearly 
three-quarters the width of a columnar side. Its surface is curved to accord with 
the re-entrant angle of the columnar. Since this angle is always more marked in 
the epizygal than in the hypozygal, a portion of the latter forms a wall for the 
facet, and may occasionally take the place of the lower straight portion of the rim. 
The extent to which the facet is sunk into the columnar varies; usually the rim 
rises straight up from the general level, but sometimes it is surrounded by a 
groove. 
The following measurements of the cirrus-facet in millimetres are taken from 
normal adult specimens: 
Diameter of nodal 
. ... 6'4 
6-0 
5T 
5’4 
4-5 
Width of side . . 
. . . . 3'9 
3-9 
3-5 
3'3 
2'7 
Width of facet . . 
. . . . 2'8 
2-8 
2'6 
2’4 
2’0 
Height of facet. . 
. . . . L5 
1-3 
1-3 
1-2 
1-1 
Cirrals: In only one 
specimen (f), and 
on only 
one side 
of it, 
is a fragment 
of a cirrus preserved (fig. 115). This consists of cirrals 1 and 2. Their transverse 
diameter is l - 3 mm.; their vertical diameter, TO mm.; the length of the fragment 
is 0 5 mm. The distal joint-face of cirral 2 is worn; its outline is more regularly 
elliptical than that of the columnar cirrus-facet; a faint fulcrum lies in its upper 
half, and towards it slope the upper and lower portions of the surface; a slight 
depression near the margin of the lower half produces the appearance of a rim. 
The upward bend of the cirrals is very slight, and probably not more than can be 
accounted for by the upward slope of the columnar cirrus-facet. 
Relations of the Species. — Differing, as it does, in almost every feature 
possible from the other Isocrini of the Veszprem district, I. Hercuniae could not 
be confused with any of them. Among other Triassic species it comes nearest to 
I. propinquus (Münster,) and in fact some of the specimens were submitted to me 
with that name already attached. Possibly the published descriptions and figures of 
I. propinquus would justify such a reference; but study of the type-specimens 
and of the abundant material of that species preserved in the museums of Munich, 
Vienna, and London enables me to state the following characters in which it differs 
from the present species. 
The relative height of the internodals in I. propinquus is about two-thirds 
that in I. Hercuniae, the average of 19 specimens being 14 - 26, as opposed to 21 
in the latter, and the extremes noted being 19 and 12 as opposed to 32 and 13, 
the diameter being taken as 100 in each case. The crenelation of the suture-line 
is more distinct at the interradial angles in I. propinquus. Münster and Laube state 
