HISTORICAL. 15 
Asterids. He also introduced a more rational terminology for the plates of 
the calyx, which is still used by Zoblogists and Palzontologists. He proposed 
the name “ Basala” for the pelvis plates of Miller, and “ 2adialia” for Mil- 
ler’s scapule and costals, including the first axillary. When the rays are 
free above the first radial, the axillary supports the arms; but when that 
plate forms a part of the calyx, it is followed by the “ Distichalia,” and these 
by the “ Palmaria”’ For the supplementary plates he introduced the terms 
“ Interradialia, Interdistichalia and Interpalmaria.” 
Miiller divided the Crinoids into three great groups: the “ Crinoidea Arti- 
culata,’ the “ Crinoidea Tessellata” and the “ Crinoidea Costata,’ which he 
defined, and of which he gave a list of the principal genera. 
Of the Articulata, to which Miiller referred Pentacrinus, Apiocrinus, Encrinus, 
and the Comatule, he said that the rays develop directly from the base of the 
calyx, and the. lower ray plates are united laterally by a skin, which is either 
naked or paved with irregular plates; that this skin is continued to the ven- 
tral disk, closing the ventral side of calyx and arms; and that the radials 
consist of three successive plates, of which the first and second, and the 
axillary and the first arm-joint, are united by muscles. 
Miiller’s Tessellata combine Miller’s “ Semiarticulata,’ and “ Inarticu- 
lata,”.and include the Blastoidea, Cystidea and the Cretaceous genus Mw- 
supites. The calyx is composed of 3, 4 or 5 basals, which are sometimes 
separated from the radials by a ring of “ parabasals.” Between the radials 
there may be “ interradials,” and between the distichals and palmars, “in- 
terdistichals,” and “interpalmars.” The “Scheitel” (ventral disk) covers 
the whole ventral surface; it is constructed of solid plates, united at their 
edges. 
The Tessellata were subdivided by Miiller into two groups: Crinoidea 
with arms, and Crinoidea without arms. To the former he referred all true 
Crinoids and the Cystid genus Caryocrinus, forms having no separate anal 
opening and no “ Tentakelfurchen ” (food grooves) upon the disk, and none 
probably upon the arms. The armless Crinoids comprise the “ Pentremites” 
(Blastoidea) and “ Sphaeronites ” (Cystidea), forms with separate mouth 
and anus. 
Miiller’s classification, although a great advance upon that of Miller, was 
not accepted by the French and English writers succeeding him; but it was 
revived later on by Ferd. Roemer and von Zittel. 
In 1842 a classification was proposed by Thos. Austin and Thos. Austin 
