Echinoid Radioles , Cidaris Hausmanni et parastadifera. 207 
When tvvo diameters are given, the former is that in the sagittal plane indicated 
by the obliquity of the base. This is not always very clear, but on the whole it 
appears that the difference betvveen the sagittal and transversal diameters is slight, 
and not markedly in favour of either. 
The shaft is slightly pyriform or swollen baculiform. It is ornamented with 
small obscurely marked pustules, closely set, either irregularly scattered or in long¬ 
itudinal series. The pustules run from 3 to 4'5 to the millimetre in each direction. 
There are no distinct grooves between the longitudinal series, and their pustules 
are not borne on ridges. 
The base is always oblique ; but the obliquity varies and is never strongly 
marked, nor does its direction seem correlated with the shape of the shaft. 
There is no distinct collerette; the annulus is rounded and smooth; the aceta- 
bular inargin is a smooth prominent ring. 
Relationsof the Form. — These resemble the radioles that Quenstedt 
(1875, p. 194, pl. lxviii, ff. 69 71) took to represent C. Hausmanni , and referred 
to C. dorsata. They resemble C. Hausmanni in size and to some extent in the 
seriation of the pustules, and they approach it in the obliquity of the base. They 
differ from the typical C. Hausmanni, however, in the absence of a marked col- 
lerette-rim and of ridges on the shaft. The Ornament is more reminiscent of C. 
Hausmanni tofacea, but from this too the specimens differ in the other characters. 
Consequently I donot think that they have any more to do with the true C. Haus¬ 
manni than Quenstedt’s specimens had, although they may indicate a Variation 
towards that species. 
Whether these small radioles should be referred to C. dorsata is another 
matter. Their characters are fairly well defined, so that they do not seem to be 
merely young forms They may possibly be secondary radioles of that species; 
but if secondary, then they might well belong to some other species of very different 
character. 
Cidaris parastadifera .* 
(Plate XIII, figs. 375—392 & Plate XVI, fig. 447.) 
1865. Cidaris parastadifera K. E. Schafhautl : N. Jahrb. f. Mineral., 1865, p. 796, pl. v, f. 8 a — d. 
1865. Cidaris cf. marginata lit. Goldfuss, K. E. Schafhautl: op. cit. p. 791. pl. v, f. 2, 2a. 
1889. Cidaris parastadifera Schafh., S. v. Wöhrmann: Jahrb. geol. Reichsanst Wien, p. 195, pl. v, f. 19. 
Diagnosis. — A Cidaroid in which the primary radioles have a micro- 
structure of fine, close-set septa Crossing in curves at oblique angles and disposed 
fan-wise near the periphery, with a small axial complex; in which normal (peri- 
pheral) radioles are baculiform, with shaft dorso-ventrally compressed, and orna¬ 
mented with regulär longitudinal ridges bearing strong, discrete, subequal pustules, 
thorn-Iike or swollen, more pronounced on one [? adapical] side; adoral radioles 
more lanceolate; adapical radioles more subclaviform; collerette low but distinct, 
smooth ; annulus rounded, smooth; acetabular margin prominent, smooth. 
Holotype, the oral surface of an Echinoid, in which the structure of the 
test is indistinguishable, surrounded by 11 radioles: original of Schafhäutl’s figure 8. 
Type-locality, Wettersteingebirge. 
This mongrel vvord (melius parastadophora) means pilaster-bearing. 
