260 Triassic Echinoderms of Bakony. 
as genotype, that name being proposed for Cidaris Klipsteini Desor non Marcou. This 
proposal and a part of the discussion has, since those pages were in type, been 
published in a separate paper on Eocidaris (Batuer, Jan., 1909, not 1908 as quoted 
on p. 86). In the course of this discussion, as also in the paper just mentioned, 
Eocidaris is restricted to E. laevispina and E. scrobiculata, the former being taken 
as genotype (p. 86). Cidaris Keyserlingi, which has very generally been regarded 
as an Eocidaris, is now referred to Miocidaris, and Eotiaris LampBerr is therefore 
not accepted (p. 85). A number of fragments are referred to Miocidarés, but for 
only two forms are new names proposed — M. verrucosus and M. planus. 
The discovery of interambulacral plates that, it is believed, belong to the same 
species as the radioles described as Anaulocidaris testudo, has caused the resusci- 
tation of that genus as a peculiar type of Cidarid (pp. 94, 138). 
An interambulacral fragment from the Cassian beds of Cserhat that seemed 
to resemble the description of Hodiadema granulatum led to a discussion of the 
genus (p. 100). It was not till the sheet containing those remarks was already 
completed that I discovered the original specimens of Hodiadema, just in time to 
insert a brief statement. Further specimens have since been placed in my hands, 
and I hope to publish a separate account. In the remarks on the type-species I have 
nothing to alter, but I now think that the reference of the fragment from Cserhat 
to Eodiadema is more than doubtful. 
In order to understand the relations of various Diademoid fragments from 
Bakony, I studied the genera with which comparison seemed likely to be profitable, 
and some of the results of this study are summarised on pages 102—117. The 
genera chiefly discussed are: Archaeodiadema Grecory, which seems to me a 
Hemipedina ; Palaeopedina Lampert, which also appears insufficiently distinguished 
from the same genus; Orthopsis Cotreau, which I am led to regard as a post- 
Bajocian modification of Diademopsis, and not so primitive as has been supposed ; 
Hemipedina Wricut and Diademopsis Drsor, which do really seem to represent 
two distinct lines of descent, although repeated modifications render it difficult to 
assign every species to its correct genus; this difficulty of discriminating the genera 
has been expressed by almost every writer on the subject, and the proposal to 
retain the prior Hemipedina as the main genus in a broad sense, while referring 
certain species to Hemipedina (s. str.) and Diademopsis as subgenera, will, it is 
hoped, serve practical convenience until our knowledge is further advanced. Finally 
Mesodiadema Neumayr receives fairly full discussion, but without examination of 
the various original specimens (such as time did not permit me to undertake) this 
cannot pretend to finality. The result of this comparative study is that two Raiblian 
species from Bakony are referred to Mesodiadema — M. margaritatum and M. latum — 
and one is regarded as an ancestral form of Diademopsis—Hemipedina (Diadem- 
opsis) incipiens. Mesodiadema latum, as subsequently pointed out (p. 229) appears 
to include the interambulacral fragment doubtfully referred by von Wourmann to his 
Cidaris Schwageri, but whether it is conspecific with the radiole that is the holotype 
of that species must remain undecided; it seems more probable that its radioles in 
Bakony are represented by some of the forms here described as Radiolus lineola (p. 234).* 
The Radioles of Triassic Echinoidea, especially the numerous forms from St. 
* It is unfortunate that in this study of the Diademoida I had not the advantage of Dr. A. 
Tornaquist's valuable paper «Die Diadematoiden des wiirttembergischen Lias». (Zeitschr. deutsch. geol. 
