Echinoid Radioles, Cidaris Wissmanni et Hausmanni. 
201 
«Cidaris» Hausmanni. 
1841. Cidaris Hausmanni H. L. Wissmann in Münster : Beitr z. Petrefactenk. IV, p. 44, pl. iii, 
f. 14 a — d. 
1855. Cidaris Hausmanni Wissmann, E. Desor, Synops. Ech. foss p. 19, pl. ii, f. 2 a—d. 
1855. Cidaris Hausmanni Wissmann, J. Koechlin-Schlumberger : Bull. Soc. geol. France (2), XII, 
p. 1064. 
1863. Radiolus Hausmanni Wissmann, H. E. Beyrich : Monatsber. preuss. Akad. Wiss. Berlin, Jahr. 
1862, p. 30. 
1865. Cidaris Hausmanni Wissmann, G. C Laube : Denkschr. Akad. Wiss. Wien, Math.-Nat. CI. XXIV, 
Abth. 2, p. 284, pl. ix, f. 13. 
1900. Cidaris Hausmanni Wissmann, E. K. Hesse: N. Jahrb. Mineral. Beil.-Bd. XIII, p. 228, f. 1. 
1904. Cidaris Hausmanni Wissmann, F. Broili : Palaeontogr. L, p. 154, pl. xvii, ff. 25, 26. 
Diagnosis. — A Cidaroid in which the primary radioles have a micro- 
structure of fine waving septa arranged in fan-like groups, with a general tendency 
to radiate from the inconspicuous axial complex. Normal radioles vary from globose 
to thin fusiform, often irregulär in shape, but not compressed dorso-ventrally; Orna¬ 
ment of longitudinal ribs bearing pustules, which may coalesce and disappear; base 
oblique to main radiole-axis; collerette short with pronounced distal rim; annulus 
not prominent, base constricted below it. 
Lectotype, the radiole figured in Münster (1841, pl. iii, f. 14 b), from the 
Cassian beds of St. Cassian, now in the Palaeontological Museum, Munich. 
History of the Species. — The type-description by Wissmann in Münster 
(1841, p. 44) gives the following characters: radioles small, of various form, pyri- 
form, fusiform, or claviform, with strong more or less granulär ribs; «Stiel» very 
short; base and annulus smooth. 
Desor (1855) noted the distinction from C. dorsata in the seriation of the 
pustules, and reproduced Wissmann’s figures. 
Koechlin-Schlumberger (1855) maintained the species, and pointed out that 
the acetabular margin and the annulus were always oblique to the main axis. 
Beyrich (1863) described many radioles found on one fragment of rock at 
Füssen. 
Laube (1865) added to the characters already mentioned the Statement that 
sometimes, especially in round shafts, there were parallel cross-grooves between the 
rows of pustules; perhaps he meant that the pustules formed transverse rows as 
well as longitudinal, an occurrence I have not noticed myself. He also said that the 
acetabulum was very small with a smooth margin. Laube’s figures illustrate the 
variety of form and Ornament, the oblique base being almost the only obvious 
feature they have in common; indeed figures b and c may possibly represent young 
C. alata. 
In this connection it may be mentioned that one of the four radioles figured 
by Klipstein (1843, pl. xviii, f. 14 a — g) as «Unbestimmte Cidariten» reminds one 
of C. Hausmanni. This specimen (Klipstein f. 14 a, b; Brit. Mus. E 4597) has 
both Ornament and base characteristic of that species, the differences being that the 
shaft is compressed, with one face ribbed rather than pustulate, and that the obli- 
quity of the base is in a direction between the sagittal and transversal planes of 
the shaft, a position which is, as we shall see, intermediate between that in C. alata 
and in C. Hausmanni. 
