MORPHOLOGICAL PART. 53 
has been substituted, at the suggestion of Prof. Zittel. But Zittel,* and the 
German Palxontologists generally, while admitting the homology, and the 
name “ infrabasalia,”’ adopted the term “ parabasalia”’ for the upper ring of 
plates in the dicyclic base, claiming that the word “ basals,” if applied to 
the dicyclic base as well, might lead to confusion. 
The practice of giving different names to sets of plates which are ad- 
mitted to be homologous was justly criticised by Carpenter,t and serious 
difficulties arise as to which term should be applied in certain groups, where 
infrabasals exist in some species and are wanting in others. Such a case is 
presented by the Apiocrinid, among which de Loriol discovered rudimen- 
tary infrabasals in two species of Millericrinus.$ This family was previously 
supposed to be monocyclic, and the base is described by Zittel as consisting 
of five Jasals, whereas in the two species above mentioned, the five corre- 
sponding plates would be parabasals. There is a similar case among the Penta- 
erinidz, in which infrabasals are represented in one genus, — Exrtracrinus. 
In the Comatulx, in which, according to Bury,§ small infrabasals occur in 
the ciliated larva, but disappear in the Pentacrinoid stages, the very same 
plates would be “ parabasals” in the earlier stage, and basals in the later. 
Carpenter is clearly right when he says that this terminology, instead of 
making it easier to students, as claimed by the German Paleontologists, 
would be the source of endless confusion. 
A different interpretation of the basal plates was given by Dr. J. Wal- 
ther.|| He accepts Zittel’s terms for descriptive purposes, but homologizes 
the infrabasals with the basals of the Monocyclica, the “parabasalia ” with 
the monocyclic radials ; and he takes the radials of the Dieyclica to repre- 
sent an entirely new element in crinoid morphology. This recalls the idea 
of Lyon,** who took the basals of the Blastoids for “ primary radials,” and 
the forked plates for “secondary radials.’ As Walther’s views are alto- 
gether out of keeping with the facts of Paleontology, and also, as we now 
know, with those of the embryology of recent Crinoids, any further discus- 
sion of the subject is unnecessary. 
The Comatule have basals only in their earlier stages; during the later 
* Handbuch d. Palaeontologie, Vol. I., p. 327. 
+ Ann. and Mag, of Nat. Hist., July 1890, pp. 5-11. 
{ Paléontologie Francaise, Tome XI., Part T., pp. 553, 566. 
§ “The Early Stages in the Development of Antedon rosacea.” Report of the Fifty-seventh Meeting of 
the British Association at Manchester, 1887, p. 735. 
|| Untersuchungen iiber den Bau der Crinoideen, Paleontographica, 1886, Bd. XXXII., p. 189. 
** Geol. Rep. Kentucky, Vol. III. p. 469. 
