72 
Triassic Echinoderms of Bakony. 
From these measurements it appears that, although the smaller and presum- 
ably younger specimens of the two species are, as might be expected, not quite so 
divergent as are the larger ones, still even they present the differences mentioned above. 
A scrobicular ring is formed by 14 or 15 secondary tubercles, between which 
are intercalated miliaries or tertiary tubercles, frequently two arranged radially in 
each of the spaces, just as represented by Laube (1865, pl. IX, f. 1) for T. subsimilis. 
The extrascrobicular surface is filled with secondary tubercles as large as, or some- 
times very little smaller than, those of the ring, while among them tertiary tubercles 
are irregularly scattered. In a this Ornament is very clearly marked, the secondary 
tubercles being mamelonate, but apparently not perforate. In the largest intertubercular 
tract, 3.6 mm. across, about 6 or 7 secondaries lie in a line, including the scrob¬ 
icular tubercles ; in a smaller tract, 2.3 mm. across, there are about 4 in a line; 
in each case miliaries intervene. In c and f the Ornament is less distinct, the tubercles 
being either ill developed, or worn down, thus producing an apparent tendency to 
anastomose. ln g, which is possibly not this species but a fragment of C. Liagora, 
the scrobicular tubercles are plainly, though slightly, larger than the extra-scrob- 
icular secondaries, while the latter together with the intermingled tertiaries are 
widely spaced and rather regulativ arranged, and a line of tertiaries borders the 
adradial margin. In g, 3 well-delined secondaries with their surrounding miliaries 
occupy 2.3 mm , while 4 secondaries occupy 2.6 mm. Setting g aside, T. subsimilis 
is seen to differ from T. persimilis, first in the scrobicular ring being more prom¬ 
inent than the extra-scrobicular secondaries, as is clearly shown in Laube’s pl. IX 
f. 1 b, secondly in the absolute paucity and relative sparseness of the extra-scrob¬ 
icular secondaries, as correctly represented in Münster’s and Laube’s figures of the 
holotype. Specimen g though in these respects approaching T. subsimilis, is plainly 
differentiated by the distinctness and regularity of its Ornament. 
The ambulacra (figs. 132, 134) are sinuous and at the ambitus their width is 
from 0.274 to 0.357 that of the interambulacrum; these ratios are very close to 
those presented by T. subsimilis. The number of ambulacrals to an ambital interam- 
bulacral is 18, the number in T. subsimilis being 15—18. Their transverse sutures 
slope slightly inanorad direction towards the radius. The perradial tract bearstworows 
of tubercles, intermediate in size between the secondary and tertiary tubercles of the 
interambulacrum, and these tubercles, being one to each ambulacral plate, form a 
regularly alternating series, except at the adoral end, where a few miliaries are 
intercalated between the two rows. There are no other tubercles on the ambulacrum, 
but a very minute miliary can with difficulty be detected on the adoral outer side 
ot several main tubercles. Münster mentions a series of tubercles outside the pore- 
helds in T. subsimilis, but they appear to be really on the edge of the interambul- 
acrals, so there is no difference between the two species in this respect. The inner 
pores are circular, or very slightly extended transversely in connection with a groove 
which leads from each pore along the orad margin of the ambulacral, on the suture 
line, to the outer edge of the ambulacrum. The outer pores are markedly elongate 
transversely and each is connected with a wider groove running along the middle 
of the ambulacral, parallel with the sutural groove, to the outer edge of the 
ambulacrum. The sides of this groove continue as a ridge round the inner margin 
of the outer pore and so separate it from the inner pore, and this portion of the 
ridge may be slightly raised into a granule. In T. subsimilis holotype this granule 
