Echinoid Radioles, Cidaris scrobiculata. 188 
«Cidaris» scrobiculata. 
(Plate XI, figs. 3836—339.) 
1841. Gidaris scrobiculaia BRAUN in MONSTER, Beitr. z. Petrefactenk. IV. p. 45, pl. iii, f. 21, a, b. 
1865. Cidaris scrobiculata Braun, G. C. Lause, Denkschr. Akad. Wiss. Wien, Math.-Naturw. Cl., 
XXIV, Abth. 2, p. 285, pl. viii b, f. 7. 
1904. Cidaris dorsata BRONN in MUNSTER (pars), F. Broil, Palaeontographica, L, p. 153. 
Diagnosis. — A Cidaroid with main radioles not exceeding 15 mm. in 
length, having a pyriform, globose, or truncate-conical shaft, the surface of which 
is covered with small deep pits irregularly distributed and having a granular border 
apparently of fused pustules. 
Braun’s description (1841) runs: «Diese seltenen kleinen birnformigen Stacheln 
zeichnen sich durch die unregelmassig auf der ganzen Oberflache vertheilten tiefen 
Griibchen aus, an deren Kanten sich keine Knoten oder Warzen zeigen. Der -Gelenk- 
kopf ist glatt, der kurze Stiel und der ringformige Leisten fein gestreift. » 
The species was accepted by every author down to and including Lause (1865), 
who, however, substituted «kugelf6rmig» for «birnformig», adding «zuweilen auf 
dem Scheitel abgeplattet». His diagnostic statement, «colli, brevi, forti, fossa articulari 
magna», is not applicable to all specimens. As regards the surface ornament, he 
specially mentions granules, and says that the pits occur between them, while 
towards the distal end the pits may occasionally give place to rounded pustules. 
Granules are in fact so easily seen, and it is so obvious that the walls of the pits 
are composed of fused pustules, that one suspects Braun’s «keine Knoten u. s. w.» 
to be a misprint for «kleine Knoten u. s. w.» 
QueEnsteDT (1875, p. 194) seems to have been unacquainted with true specimens 
of this species, but compared the form with that of similar small radioles assigned 
by him, no doubt correctly, to C. dorsata. 
Brom (1904), after study of the original material and of radioles from the 
«Pachycardientuffe» of the Seiser Alp, has made the species a synonym of C. dorsata. 
Material from the Tyrol. — The British Museum contains six radioles 
labelled «St. Cassian» from the Kuipstetn Collection, No. 642 (regd. 36489 & E 9464), 
and 12 specimens out of the material reported on by Brom, from the Pachycardien- 
tufte, Tschapit-bach, Seiser Alp. (regd. E 4702, E 9463). In addition to these, | have 
examined the original specimens at Munich and Vienna. 
Dr. Brom (1904), while recognising that his material from the Pachycardien- 
tuffe agrees, in the main, with C. scrobiculata, has made that name a synonym 
of C. dorsata. His reasons appear to be: 1. that in the Cassian beds C. scrobiculata 
is rare; 2. that the radioles from the Pachycardientuffe may owe their peculiarities 
to an exaggerated deposition of stereom, such as is observed also among the 
contemporary Brachiopods, Lamellibranchs, and Gastropods; 3. that if the granulation 
of their surface were rubbed down by external, mechanical agencies, they would 
agree with Braun’s diagnosis of the Cassian C. scrobiculata. 
The first argument would be a reasonable one if the Cassian forms alone 
were considered; but in the Pachycardientuffe the radioles in question are quite 
numerous. It should also be remembered that other distinct and universally accepted 
species among the St. Cassian radioles are equally rare. 
