REPORT ON THE CRINOIDEA. 397 
to the Echinoidea and partly to the Asteriadea, cannot by any means be applied to the 
homologous parts in the Crinoid,” 7.e., to the basal plates. Lovén,’ however, objects to the 
extension of the latter name to the so called genitals of Urchins and Starfishes, because 
the position of their apical plates, “while basal in the Crinoidea, is culminating in the 
Echinoidea and the Asteriadea, and consequently any appellation involving the notion of 
~ a basal position must be avoided.” There is undoubtedly some force in this objection ; 
and I have long been endeavouring to find some general expression that would conveniently 
describe the interradial plates in the apical system of all Echinoderms. Not having 
succeeded in this quest, I have been obliged to fall back upon the word “ basals.” The 
interradial position of these plates in the calyx of a Crinoid, as defined by Miiller,’ is 
now universally recognised, and the use of the word is not likely therefore to lead to any 
confusion respecting the position of the plates with regard to the general symmetry of 
the Echinoderm type; while it has the further advantage of avoiding the multiplication 
of “terms already too numerous.” As Lovén objects to the use of “basals” for the 
reasons given above, he seeks to avoid the introduction of new names by reviving the old 
term “costals” of Miller. To this there could be no possible objection were it only 
employed in the sense in which it was generally used by Miller, but this is unfortunately 
not the case. In seven out of the nine genera which were described by Miller as 
having costal plates, this term was used for the radial plates of the calyx ; while it was 
only in describing some species (not all) of Cyathocrinus that he employed the term costals, 
for the interradial plates of the calyx or basals, and in the case of Marsupites he gave this 
it has 
always been considered allowable to suggest the use in a strict sense of a term elsewhere 
vaguely applied.” This is of course quite true, but the term should surely be limited to 
that sense in which it was most generally used by its author. This is not the case, 
ce 
name to the under-basals. Lovén admits this inconsistency,* but adds that 
however, with Lovén’s revival of the term “ costals,” for he employs it to designate the 
basal plates which were only called costals by Miller in four out of the many species 
described by him; while he applied this name to the radials in all the other cases in 
which he used it at all, except in that of Marsupites. I cannot help feeling, therefore, 
that this revival of a name which has been disused for half a century is somewhat 
inexpedient, and is likely to lead to a confusion between the radial and interradial 
plates of the apical system which it is very desirable to avoid. Every one knows that the 
interradial abactinal plates of an Urchin or Starfish are not situated at the base of its 
body as they are in a Crinoid ; and this reservation being made I do not see that there 
can be any objection to calling them basal plates. This would avoid all possibility of 
any confusion with respect to their position as regards the general symmetry of the 
1 On Pourtalesia, loc. cit., p. 63. 
2 Itmay be noted with respect to this point that when Lovén inverts an Urchin for a better comparison of its calyx 
with that of a Crinoid, his “ costal” plates (the genitals) really do become “ basal” in position (see p. 414). 
3 Bau des Pentacrinus, loc. cit., p. 25. 4 On Pourtalesia, loc. cit., pp. 63, 64. 
