216 Triassic Echinoderms of Bakony. 
of ornament, that on one face being four smooth ribs, tending to break into pustules 
at their proximal ends, while that on the other face consists of five (one incomplete) 
coarsely pustulate ribs, becoming smoother distally ; on each side is a rib of inter- 
mediate character, completing the total of 11 ribs. But between the smooth ribs 
are also incipient ribs of fine pustules, five in all. 
The reference of all these specimens to C. decoratissima may be open to 
question, but on the one hand I see no serious objection to this course, and on 
the other I can find no undoubted Raiblian species in which they would be more 
fittingly placed. To place them here is, at any rate, better than making a new species. 
Relations of the Species. — The name is doubtless due to <eine 
gewisse Ahnlichkeit mit Cidaris decorata>» (WourMann, loc. cit), but if the micro- 
structure is such as it has here been inferred to be, then it suggests that C decora- 
tissima cannot be a Raiblian mutation or direct descendant of C. decorata. The 
micro-structure of the shaft is more like that of such an irregular formas C. Waechteri, 
but scarcely so irregular as C. dorsata. Some of the specimens from the Cassian 
of Bakony herein assigned to C. Waechteri have an ornament closely resembling 
that of C. decoratissima, and I am therefore inclined to place the Raiblian species 
with that group. The coarser ornament is also not unlike that of C. similis, but 
the micro-structure is obviously different. 
Radiolus raiblianus n. sp. 
(Plate XIII, figs. 399—403, and Plate XVI, figs. 450, 451.) 
Diagnosis. — A Cidaroid in which the primary radioles have a micro- 
structure of fine, slightly wavy, dichotomising septa, joined by distinct trabeculae, 
in the outer layer; forming larger meshes of irregular arrangement in the middle 
layer; and passing through a still more irregular layer into an axial lumen. In which 
normal peripheral radioles are baculiform, not striate, ornamented with small pustules, 
set as a rule in longitudinal rows, but also assuming an oblique or transverse 
arrangement, especially on one face of the shaft; collerette a low groove; annulus, 
prominent, rounded, smooth; acetabular margin prominent, smooth 
Material. — Three complete radioles and 22 fragments of radioles from 
the Raiblian of Jeruzsalemhegy, including two from which microsections have been 
prepared. The more important of these are lettered a—q. 
Holotype. — The radiole shown in Plate XII, figs. 399, 400, and lettered e. 
Description of Specimens. — Though differing among themselves in 
shape and ornament, these specimens have the general characters of the Cidaris 
Wissmanuni-Waechteri group. The shape varies from sublanceolate, chiefly in 
smaller specimens, to baculiform and slightly tapering; the dorso-ventral compression 
is very slight, being at most 0°15 of the greatest diameter (specimen /). From the 
accompanying table of measurements it will be seen that the species attains twice 
the size of any specimens of C. Wissmanni or C. Waechteri from Bakony, and 
is still larger than any C. parastadifera. \n the three complete specimens, a, B, e, 
the average ratio of greatest diameter to length is 022. These specimens are 
certainly among the shorter and more swollen forms of the species, and the ratio 
must have been less in the more baculiform radioles such ash and j (figs. 401, 408). 
If the ratio in 7 were no less than in e, the length of 7 would be 365 mm. But 
