196 Triassic Echinoderms of Bakony. 
this alone that Dersor founded his species. It is part of a shaft from St. Cassian, 
and is preserved in the Palaeontological Museum, Munich. 
Notes on Cassian material. — Specimens closely resembling the 
holotype, though not abundant, are to be found in all the larger collections. Five 
fragments, of which one has recently been used for a transverse micro-section, 
were labelled «Cidaris spinosa M.» in the Kurpstein Collection of the British Museum 
(regd. 36487). Characteristic specimens were found associated with C. similis in 
the Geologische Reichsanstalt, Wien, and labelled C. Wissmanni. Similar confusion 
of these two forms obtained in the British Museum and in others, but confusion 
with C. Waechteri is no less common. 
No complete radioles are known, but Lause has supplemented Mubnsrer’s 
account with the figure (pl. x, f. 8 a, b) of a proximal portion. 
The stoutest fragment in the British Museum (36487) has diameters of 5 and 
45 mm., including the pustules, or about 4 and 3°5 mm., excluding them. In this 
specimen the pustules are narrow and longitudinally extended, but not very thornlike. 
The fragment appears to be distal end of a supra-ambital or circumapical radiole, 
since it is not markedly bilateral and ends in a depression containing small pustules. 
A well-preserved and highly characteristic fragment from the middle of a shaft 
(E 4700) has diameters 3°4 and 2°6 mm, including the pustules, and about 2°1 
and 1°9 mm. excluding them. The pustules of the side and of one (? adapical) 
face are markedly thorn-like, becoming almost cylindrical at their ends; those of 
the other (? adoral) face are little more than granules, but are quite distinct. All 
the pustules have a strong rake distalwards. 
The pustules differ from those of C. similis in being further apart, not borne 
by ridges, often far more thornlike, and usually quite irregular in distribution. The 
last fact renders it difficult to compare the number with that of C. similis, but in 
so far as one can speak of longitudinal rows at all, one can estimate their number 
at from 7 to 10. In the smaller shafts it is usual for there to be a row of strong 
thorns down each side and two rows on the supposed adapical face, while on the 
other face are 3 or 4 rows of granular pustules. 
The surface of the shaft between the pustules appears quite smooth in the 
better preserved examples, but here and there, especially in weathered specimens, 
the micro-structure of the stereom is obscurely exposed; this appears irregular, even 
more so than one would expect from a transverse section, and no such clear 
longitudinal striation as characterises C. similis can be detected. On the handle 
of the shaft, however, the longitudinal striation may be more distinct, as shown in 
Laupr’s figure 8 b. This is confirmed, though not very strongly, by the proximal 
half of a radiole in the Kuipsrein Collection (E 8422). Here the collerette is succeeded 
by a smooth handle, about 2 mm. long, with distinct striae. “The pustules of the 
shaft, however, are more numerous and more crowded than in the holotype and 
similar forms, so that the specimen may be more closely allied to C. Waechtert. 
The collerette in Lausr’s figure 8 b is 1 mm. long, tapering distalwards, and 
more coarsely striated than the shaft. In E 8422 it is relatively shorter and is obscure. 
The annulus, in the same figure and specimen, is finely crenelate, and does 
not project from the collerette to the same extent as in C. similis. 
The margin of the acetabulum is described and figured by Lauper as deeply 
crenelate. In E 8422 there are traces of crenelation. 
