44 
'Triassic Echinoderms of Bakony. 
Diameter. 
. 1-8 
1*8 
1-9 
1-9 
1-9 
2-0 
2-2 
2-5 
2'5 
2-7 
Height of internodal . 
. F05 
1-1 
09 
F06 
1-07 
0-96 
075 
0-86 
l'O 
0-96 
Height of epizygal . . 
IT 
— 
08 
0-8 
1-0 
l'O 
09 
1-0 
— 
1-0 
Diam. 100, height = . 
58 
61 
47 
55 
56 
48 
34 
34 
40 
35 
The average of 22 specimens, with diameter taken as 100, gives the height 
of an internodal as 57, the mean between the extremes being 58'5. 
The internodes are short; out of 16 specimens taken at random 6 had four 
internodals, and 10 had five, the hypozygal being reckoned in each case. Fracture 
at the syzygy is fairly frequent, but there are some cases in which the syzygy 
remains unbroken, with its suture-line scarcely discernible (fig. 82), while on the 
other hand there are many isolated columnals. 
There is very little difference in size between the internodals; but the hypozygal 
in usually the shortest. 
The swelling of the epizygals, though manifest to the naked eye (fig. 80), 
results in a very slight increase of diameter, since it is partly compensated by the 
inuch greater radial excavation of these columnals. Thus, in a fragment with an 
internodal diameter of 2'7 mm., the diameter at the syzygy is only 2'75 mm., an 
increase of less than 2 per cent. 
The sculpture of the normal joint-faces (figs. 77—80) is clear-cut, and the 
crenellae surround the petal regularly, with little Variation in size; the interradial 
peripherals are as usual the shortest, while the adradial peripherals are the longest, 
and are parallel to those of the radial ridge-groups. The following are measurements 
of a normal columnal in millimetres: diameter, 2*0; IR, 1*2: r, 0'8; from centre 
to end of petal-floor, 0'85 ; longest crenella, 0‘4; shortest crenella, 0 - 2 or less: width 
of crenella, O'l. The crenellae may widen, almost imperceptibly, towards their outer 
ends, but are not confluent. 
The epizygal face (figs. 81, 88) is raised radially and is concave interradially. 
The appearance varies in intensity, and also with the extent of the lobation ; but 
no essential difference arises. The hypozygal face (figs. 84, 87) is as a rule somewhat 
flatter than that of the epizygal; sometimes the petal-floors are raised as usual in 
the genus, but they are often slightly concave. 
Although the depressions for the cirri cut slightly into the hypozygal, the 
cirrus-facet itself is wholly in the epizygal (figs. 82, 83, 85, 86, 89). The position 
of the lurnen has not been made out. On the distal face of cirral 1, the dice-box- 
shaped fulcrum, with the lumen below it, appears to be characteristic. The following 
are measurements of a normal example in millimetres: diameter of epizygal, 2‘7 ; 
width of side, 1'9; transverse diameter of facet, 0'8; vertical diameter of facet, 
07 ; length of fulcrum, 04. There is no trace of further cirrals. 
Relations of the Species. — In side-view it is not easy to distinguish 
the larger specimens from I. ccindeldbrum. The relative height of the columnals, 
when all are considered, is greater than that of any other species from this district; 
but size for size it about equals that in I. candelabrum . There are, however, too 
many differences between the two species to allow one to suppose that I. scipio is 
merely the young of I. candelabrum. The swelling of the epizygals is inore marked 
and approaches that of I. sceptrum, from which it is distinguished by the many 
features subsequently detailed. The vermicular area, the radially directed adcentral 
