ie. _Diadematoid Radioles, k. lineola. se. eee ; 231 
their retention, however, it is clear that the curve for the whole assemblage would 
be distinctly double-crested, and would in fact form two curves separated by a clear 
interval of about 1°75 mm. This justifies the erection, at least for descriptive 
purposes, of two varieties. 
Radiolus lineola var. major. 
(Plate XIII, figs. 420, 421, and Plate XVIII, fig. 457). 
Diagnosis. — Radiolus lineola with mean diameter of radioles about 
26 mm.; surface always smooth. 
Holotype, the original of Pl. XIII, fig. 420, the same as the holotype of the 
species. 
Material from Bakony. — Jeruzsdlemhegy, 24 fragments; from Cutt- 
ing I on the Veszprém-Jutas railroad, 5 fragments labelled bed e, and 11 with no 
horizon assigned. All these are Raiblian. 
Description of Specimens. — These radioles are nearly all cylindrical 
or slightly compressed. Of bicarinate forms there are only two from Jeruzsalemhegy 
and one, rather doubtful, from Cutting I; and, since these are of small diameter 
(1°85 and 2°00 mm.) even in their greatest width, they might possibly be more 
correctly placed with var. minor. 
The length of a complete radiole may be estimated from the fragments to 
have reached about 45 mm. The largest fragment with base is 16°38 mm.; one 
without base or any sign of tapering reaches 13°2 mm. In a radiole of 3°4 mm. 
diameter in the shaft, the diameter at the annulus is 4 mm., and at the beginning 
of the collerette 3:9 mm.; the height of the base to the top of the annulus is 2°5. 
In a radiole of 2°6 mm. diameter, the diameter at the annulus is 3°7 mm. The 
large annulus, tapering collerette, and straight-sided shaft, remind one of a jousting- 
lance, and are distinctive of the species among the Bakony radioles, though the 
shape is, of course, common to many Diademoida. 
The microstructure is difficult to make out, owing partly to closeness 
of grain, partly to secondary calcite. When the axial lumen is filled with such 
calcite, it is hard to distinguish its limits in a thin section or to be quite sure that 
the irregular outlines and fractures of the imperfect crystals do not represent an 
axial complex. In a radiole of 2°7 mm. diameter, the width of the lumen is about 
1-4 mm., the thickness of the wall thus being about one-quarter the diameter of 
the radiole. 
The wall is composed of radiating septa, which can only be seen clearly in 
places (as represented by the darker patches in fig. 457). The evidence of the 
section figured and of another, also from Jeruzsalemhegy, suggests that the septa 
did not dichotomise as they do in most of the Cidaroid radioles, and, on the other 
hand, that they did not form solid wedges as they do in characteristic Diademoid 
radioles. Close to the lumen the septa seem to form a dense layer, showing to 
the naked eye or a simple lens as a dark band. This is not so definite as to be 
called an axial sheath, but may represent an incipient stage of that characteristic 
Diademoid structure 
