Crinoide a, Pen tacrininae. 
47 
The position of the cirrus-facet on the deep radial excavation seems to have 
done away with the need for any special excavation of its own. The articular sur- 
face (hg. 96) is therefore comparable with the distal face of cirral 1, in such species 
as have that cirral deeply sunk. No cirrals are preserved. The following measure- 
ments in millimetres are from characteristic nodals: 
Diameter of nodal. 
. 2'2 
1-9 
P8 
Width of its side. 
. P3 
P15 
1-3 
Transverse diameter of facet . . 
. 0-9 
0'6 
075 
Vertical diameter of facet . . . 
. 0-5 
0'4 
0-45 
Abnormal specimen, — (PI. IV, fig. 101.) One of the eight fragments from 
bed e of Cutting VI on the Veszprem-Jutas Railway consists of one complete inter¬ 
nodal and the greater part of another. It presents several peculiarities. Transverse 
section strongly quinquelobate, almost stellate. Diameter and height, both T4 mm., 
this ratio being quite exceptional in Isocrinus. Side-faces slightly depressed on the 
interradial angles at half the height, suggesting fusion, or possibly incomplete Sepa¬ 
ration, of two columnals. Suture-line crenelate all round, but there are radial pores. 
Normal joint-face (subsequently broken) though rather worn showed a pattern gene- 
rally similar to the norm, with at least eight peripheral crenellae in each petal; 
but a radial canal passed from each pore to a rim round the lumen, so that the 
adradial crenellae did not form gables. Possibly the specimen came from the 
proximal region of a stem. Among the normal specimens there is only one face so 
stellate, and that one is epizygal. 
Relations of the Species. — The abundance of material enables one to 
found this species with considerably more confidence than some. It is besides 
remarkably well characterised. No doubt it is closely related to Isocrinus scipio, 
and it is possible that here and there a worn or ill-preserved specimen may have 
been confused. The measurements of the two species appear much the same; but, 
taking a large series, one notes that in I. sceptrum the relative height of the 
internodals is less, while the epizygals are higher than the internodals, and the 
hypozygals lower, more constantly and to a greater degree than is the case in 
I. scipio. While five is the maximum number of internodals observed in I. scipio, 
dt is the minimum in I. sceptrum. The syzygial union appears to have been firmer 
in I. scipio. The joint-faces of the two species are very similar, but the radial 
direction of the adcentral perradial crenella has not been observed in I. sceptrum, 
and the crenelation of the syzygies is less. All these are small points, but not 
without significance. It is however, in the sculpture of the side-faces that the differ- 
ences are most obvious, and especially in the nodals. The interradial ridges of 
these ossicles are finer and more pronounced in I. sceptrum, while they do not 
pass on to the hypozygals as in I. scipio. The cirrus-facets also are different. 
Considering the species without reference to the localities and beds from which 
the specimens have been obtained, one would regard I. sceptrum as descended 
from I. scipio, and as more specialised than it. I. scipio seems to be more advanced 
than I. candelabrum, which I am inclined to consider as the most primitive of the 
true Isocrini from this district. All three species, however, are found on the same 
horizon. 
