Echinoid Tests, Cidaroida. : 83 
the species subsequently described as Mesodiadema margaritatum are reminiscent 
of Triadocidaris. It has in consequence been a difficult matter to decide where to 
place these two species; indeed | originally referred specimens a and b to Meso- 
diadema with a different trivial name, and | am far from claiming the present decision 
as inevitable. 
Miocidaris. 
1887. AMiocidaris L. DoOEDERLEIN, «Japanischen Seeigel», p. 40. 
1887. Eocidaris Desor [pars], L. DOEDERLEIN, op. cit., p. 39; non A. TORNQUIST (1896), nec 
J. Lampert (1900). 
1899. Eotiaris J. LAMBERT, Rev. crit. Paléozool. III, p. 82, April. 
1900. Miocidaris DorED, em. J. LAMBERT, Bull Soc. Sci. Yonne, LIII (1), p. 44. 
1900. Eotiaris J, LAMBERT, op. cit., pp. 38, 39, 40. : 
This synonymy does not include all the genera (Cidaris, Archaeocidaris, 
Permocidaris, etc.), to which various species of this genus have been referred by 
one author or another. In addition to Mtnster (1841), Kurpsreis (1843), Desor 
(1855), Lause (1865), Quenstept (1875), see further: 
1855. G, &. F. SANDBERGER, «Die Versteinerungen des Rheinischen Schichtensystems in Nassau». Wiesbaden. 
1885. W. WaAaGEN, «<Palaeontologia Indica, Ser. XIII, Salt Range Fossils, I. Productus Limestone 
Fossils, 5 .... Echinodermata». Calcutta. 
1896. A. TORNQUIST, «Beitr. z. Kenntniss v. Archaeocidaris», N. Jahrb. f Mineral., 1896, II, pp. 27—60, pl. IV. 
1897. A. TorNQuiIst, «Das fossilfiihrende Untercarbon .... in den Stidvogesen, III .... Echiniden», 
Abh. geol. Karte Elsass. V, pp. 723—802, pls. XX—XXII. 
1898. E. SPANDEL, «Die Echinodermen des deutschen Zechsteins». Abh. naturhist. Ges. Niirnberg, XI, 
pp. 17—45 & 48, 49, pls. XII, XIII. 
Diagnosis. — A Cidarid of moderate size, with the adradial margin of the 
interambulacrum sharply bevelled on the inner surface, and usually, if not always, 
denticulate, thus flexibly imbricating over the ambulacrum. Interambulacral plates 
relatively few, often wide, with scrobicules circular or elliptic, distinct or confluent, 
With main tubercles small or of medium size, having crenelate bosses. Podial pores 
not yoked (?). 
History of the Genus. — Miocidaris was established by L. DoEDERLEIN 
(1887, p. 40) with a diagnosis of which the following is a translation: «Triassic 
and Jurassic Cidaridae of moderate size, with thin test, with edges of ambulacral and 
interambulacral fields fitting over one another in articular union; primary tubercles 
small, crenelate ; scrobicular areas round, slightly sunk; pores not yoked». 
«Species Klippsteini [sic], ? subnobilis from Trias of St. Cassian, and amalthei, 
arielis and others, from Lias and Dogger.» 
In accordance with this list it seems advisable to regard as genotype the 
species first mentioned. There were in 1887 two, if not three, species from the 
Cassian Beds to which the name Klipsteini had been attached, and it is of 
course to the first-established that the name must be confined, namely to Cidaris 
Klipsteini J. Marcou, 1847.' This, however, heing based on a radiole only, is 
obviously not the one intended by Dorpertein. The next in date is Cidaris Klipsteini 
E. Drsor (March, 1855, p. 4), based on two interambulacral fragments figured by 
KurpstEIn (1843, pp. 273, 274, pl. XVIII fig. 15, 16) and now in the British Museum 
(regd. 36512, 36513). These appear to belong to a single species, but it is advisable 
1 For discussion of this species, of which C.ampla Drsor 1858 is a synonym, see later, p. 171. 
6* 
