Echinoid Radioles, Cidaris alata. 
175 
dorso-ventrally compressed, the compression being greatest in the peripheral radioles 
which have slight lateral vanes (alae) separating a more pustulate adapical face of 
the blade from a smoother adoral face. Collerette short, with fine longitudinal striae. 
Type-description: Agassiz, 1840, Nouv. Mem. Soc. Helvet. IV, p. 74. 
Type-figures: tom. cit., pl. xxi a, ff. 5 a, b. 
Type-locality: Buchenstein in Ampezzo district, Tyrol. 
Lectotype: following Desor, 1885, I take the original of Agassiz’ cast 
X 23 (Pl. XI, üg. 273), said to be in the Berne Museum. 
This is divided into three sub-species, probably to be regarded as mutations. 
« Cidaris » alata typica. 
(Plate XI, figs. 273, 274.) 
Diagnosis. — C. alata in which the peripheral radioles are sub-elaviform 
or sub-baculiform, with vanes very slightly developed, pustules subequal on ad¬ 
apical and adoral faces, of relatively moderate size and irregularly disposed; with 
long axis slightly or not at all bent. 
Type-description, type-figures, type-locality, and lectotype, 
same as for the species. 
Material from Bakony — Perhaps to this form should be assigned 
two radioles from the Cassian beds of Cserhät (Leitnerhof) lettered a & b. These 
are flattened, but with no vanes; the adapical face bears the coarser granules 
(fig. 274). 
« Cidaris » alata subalata d’Orb. 
(Plate XI, figs. 275—279, and Plate, XIV, fig. 440.) 
Diagnosis. — C. alata in which the peripheral radioles have the blade 
clearly compressed; with distinct vanes or side-keels, which may meet proximally 
on the adapical face ; with pustules of adoral face usually in longitudinal rows and 
tending to form longitudinal ridges distally ; with coarser pustules on adapical face, 
displaying a frequent tendency to lie in rows; with longitudinal axis of blade bent 
more adorally than that of the handle. 
Type-description: Münster 1841, loc. cit. supra. 
Type-figures: Münster 1841, pl. iv, f. 2. 
Type-locality: St. Cassian. 
Lectotype: the original of Münster 1841, pl. iv, f. 2 c. 
Material from Bakony. — Three radioles from the Cassian beds of 
Cserhät (Leitnerhof), lettered c to e, and one from Section XI, bed i, lettered a, 
seem appropriately placed under this form. 
The chief specimen from Cserhät ( c ) is a peripheral radiole (figs. 275, 276), 
devoid of base, 16'2 mm. long, approaching cylindrical, with slight but distinct 
vanes; its adoral face bears a fine shagreen Ornament, with a slight tendency to 
run in longitudinal rows; its adapical face bears Ornament more pronounced and 
more linear : the distal end is rounded and bears coarser pustules. 
The two other radioles from Cserhät (d & e) are obscure. In both of them 
the Ornament is markedly linear (fig. 277). 
