Crinoidea, Pentacrininae. 
49 
The beds at the first three localities are of Raiblian age, Those at Cserhät 
are Cassian, a fact which throws further doubt on the identity of the speciemens 
from there. I have no further evidence as to the age of the beds at Kökepalja 
and Länczi. 
Description of the Specimens. — Although Isocrinus Hercuniae is 
clearly characterised, yet the very multiplicity of characters, combined with their 
wide Variation, has rendered it difficult to combine lucidity with brevity in the above 
diagnosis. It is therefore advisable to repeat the Statements in the following full 
description. 
Transverse section (fig. 117) may be a pentagon, a star, a slightly excavate 
star, a rounded star, or a slightly marked pentapetalon. The excavation and the 
rounding of the angles are greater in columnals just above the nodes; excavation 
may also have been greater in the proximal region of the stem; but some columns 
as a whole may have been more excavate than others, for the extent of excavation 
and lobation do not seem to vary with the diameter of the columnals. In a few 
cases the concavity of the sides, in what would otherwise have been a slightly 
excavate star, is interrupted by a slight radial elevation (fig. 104). 
One stellate fragment, of four columnals, is regularly hexagonal.* (PI. IV, 
figs. 106, 107). 
The following measurements in millimetres are taken from normal internodals: 
Diameter. 
. 2-5 
2-8 
2-8 
3-3 
3'5 
3-5 
3‘8 
3-8 
4'2 
4-3 
Height. 
. 0'8 
0‘9 
0"65 
0'8 
PO 
0*7 
PO 
.0-9 
0'9 
Pl 
Diam. = 100, height = 
32 
32 
23 
24 
28 
20 
26 
23 
21 
25 
Diameter. 
. 4-3 
4-5 
4-5 
47 
5-2 
5-3 
5-4 
6-1 
6-6 
6-7 
Height. 
. 07 
0-8 
0*7 
0-96 
0'9 
0-9 
PO 
PO 
1‘2 
0-9 
Diam. = 100, height = 
16 
17 
15 
20 
17 
17 
18 
16 
18 
13 
The following are 
measurements 
of nodals 
in millimetres: 
Diameter. 
3-9 
4-5 
4’6 
4’9 
5.3 
5-4 
5-7 
6-2 
7'2 
Height. 
l’O 
1-3 
1-2 
P2 
1-4 
P3 
P5 
P5 
1'5 
Diam. — 100, height = 
25-6 
28 
26 
24 
26 
24 
26 
24 
20 
* This is a very rare occurrence. P. H. Carpenter (Challenger Report, Stalked Crinoids, p. 38) 
says : «In all the Pentacrinidae there are invariably five rays. I have never met with any exception to 
this rule». In an Appendix on «Sudden Deviations from Normal Symmetry, chiefly in ,Neocrinoidea‘,» 
{Quart. Journ. Geol. Soc. XLV, p. 168; Feb. 1889), I was able to quote five examples of deviation 
from pentamerism in Isocrinus and two in Balanocrinus ; but all these were four-rayed. Tetramerous 
stem-fragments of Isocrinus have also been figured by M. R. Rosinus (Tentaminis de Lithozois ac 
Lithophytis, Tab. V, Classis H, ff. 1—4; 1719), by J. Parkinson (Organic Remains, II, pl. XIII, f. 59 
1808), and in I. tuberculatus by E. F. Honnorat («Note sur le Pcntacrinus tuberculatus .» Bull. Soc. 
Sei. lit. Basses Alpes, pl. fig. 11; 1883). The two stems of Isocrinus jurensis with six lobes, fighred 
by P. de Loriol, (Paleont. Francaise, Crinoides Jurassiques, pl CXLIV, ff. 7 & 10; 1886) are not 
regularly hexamerous. Bateson, in his «Materials for the study of Variation» (p. 436; 1894) was 
unable to add any instances. Lissajous {Bull. Soc. Hist. Nat. Macon, Nos. 16, 17, p. 22 ; 1900) has 
described a stem-fragment of Balanocrinus subteres with six petals on the joint-face, but four cirri at 
the node. Honnorat (loc. cit., ff. 12, 13, 14) has figured one irregularly heptagonal, and two almost 
regulär hexagonal columnars of I. tuberculatus ; he mentions five hexagonal, of which he describes 
three as «geometriquement reguliere». These last are the only cases of regulär hexamerism in Isocrinus 
that have come to my knowledge, with the exception of the specimen of I. Hercurvae here figured. 
Resultate der wissenschaftl. Erforschung d. Balatonsees. I. Bd. 1 T Pal. Anh. 
4 
