HISTORICAL. 138 
to be struck by the resemblance they bear to the crown of Pentacrinus, and 
he pointed out that the pentagonal plate at the base of the subglobose body 
of the Comatulz occupies the position of the first column joint of the 
“ Crinoidea.” 
Miller subdivided the Crinoidea into four groups: the ArTICULATA, to 
which he referred the genera “ Apiocrinites, Encrinites and Pentacriniles ;” the 
SEMIARTICULATA with “ Poferiocrinites;” the INARTICULATA with “ Cyathocri- 
nites, Actinocrinites, Rhodocrinites, and Platyerinites ;”’ and the Coapunata with 
“ Eugeniacrinites.” His primary groups were based upon the mode of union 
between the stem and calyx, and between the latter and the arms; his 
genera upon the number and arrangement of the plates in the dorsal cup. 
Considering that in 1821 only about twenty-five species of Stalked Crinoids, 
recent and fossil, were known, and many of them only from fragmentary 
specimens, we cannot help admiring the genius of Miller, who brought 
order out of chaos, and laid the foundation of the present classification of 
the Crinoidea. His genera have been generally accepted, and are now rec- 
ognized as the types of well-marked families, 
Miller introduced an elaborate terminology, but unfortunately did not 
always apply his terms to the same parts. In some of his genera he gave 
the term “pelvis” to the proximal ring of the plates witliin the calyx, in 
others to the plates of the ring above. In Apiocrinus and Actinocrinus he 
called the radials “ first costals;” the succeeding ones “ second costals,” and 
the first axillaries “scapule.” In Platycrinus, however, and in Poteriocrinus 
and Cyathocrinus, the radials are his scapule, and are followed by arm plates. 
Platycrinus, according to Miller, has no costals at all; but in the dicyclic 
Cyathocrinus and Poteriocrinus costals are said to be represented by the plates 
of the interradial basal ring. 
A year after the appearance of Miller's work, Schlotheim published the 
first part of the Supplement to his Petrefactenkunde,* reproducing therein 
Miller's figures together with his own, and adopting his generic and specific 
names. A year later, however, in the second part of that work, he withdrew 
Miller’s generic names, and referred all Stalked Crinoids back to Enerinus and 
Pentacrinus respectively. 
Goldfuss in his great work + adopted Miller’s classification and termi- 
nology. Cumberland ¢ did not consider Miller’s name “ Crinoidea” appro- 
* Nachtrige zur Petrefactenkunde, 1822-1823 (2 Bande, mit 37 Kupfer-Platten), 
+ Petrefacta Germania, Diisseldorf, 1826-1833. 
} Reliquie conservate, Bristol, 1826. 
