932 
MR. P. H. CARPENTER ON A NEW 
the separation of the first radials by the calyx-interradials. Walcott * has recently 
pointed out that a new species, which he has described as possessing this character, 
“ departs from the typical form of Glyptocrinus,” and he suggests its reference to 
another generic type. Miller, however, regards this striking difference in the posi¬ 
tion of the lowest interradial as of no systematic value whatever, even for specific 
classification. For he identifies Reteocrinus gracilis (Wetherby), with a type pre¬ 
viously described by himself as Glyptocrinus angularis, and since recognised by 
Wachsmuth as a true Glyptocrinus. The lowest interradials rest “ between the 
upper sloping sides of the first radialswhile in R. gracilis the radials are widely 
separated laterally, and the lowest plates of the irregular interradial series rest upon 
the basals. This feature also occurs in four species which are referred by Miller! to 
Glyptocrinus , although in G. decadactylus, which he takes as his type, “ the regular 
interradial areas have one plate resting upon the primary radials! ” 
But Miller goes even further than this. He establishes a new genus, Gaurocrinus, 
for types hitherto described under Glyptocrinus, but possessing a dicyclic base ; and 
he refers to it five species, two of which are new. In one of these, and in the three 
species previously known, the lowest interradials rest upon the basals. But in 
Gaurocrinus splendens, n.sp., the large hexagonal basals are “not truncated upon the 
upper face by an interradial.” Miller’s mode of classification, therefore, totally 
disregards such important morphological differences as the separation or lateral union 
of the primary radials ; and I cannot believe that it will find acceptance among 
philosophical palaeontologists. 
Gaurocrinus differs from Glyptocrinus in having a dicyclic base,! t^ a f °f Glyptocrinus 
* “ Descriptions of new species of Fossils, from the Trenton Gronpof New York.” 35th Ann. Report 
N. Y. State Mas. Nat. Hist., p. 2 (of separate copy). 
f “ Glyptocrinus redefined and restricted, Gaurocrinus Pycnocrinus, and Compsocrinus established.” 
Journ. Cincinn. Soc. Nat. Hist., Dec., 1883, vol. vi., pp. 217-228. 
X It is much to be regretted that Mr. Miller still uses the empirical and utterly irrational nomen¬ 
clature, which is now being’ gradually replaced by a system based upon sound morphological considera¬ 
tions. He remarks that “ the policy of changing the nomenclature may well be doubted, and ought not 
to be entered upon without the clearest conviction that, by so doing’, error of some kind is being 
eradicated.” No better illustration of such an error could be found than his statement that Gaurocrinus 
“ is primarily distinguished from Glyptocrinus by possessing five sub-radials.” This name was given by 
de Koninck to the so-called parabasals of Muller, “afin de fame comprendre qu’ils alternent avec les 
radiales;” and since “the presence or absence of sub-radial plates is regarded of special generic import¬ 
ance” by Mr. Miller, we are led to conclude that the “basals” of Glyptocrinus (Miller), in which 
sub-radials are absent, do not alternate with the radials. But this is exactly contrary to the fact! Sub- 
radial plates, alternating with the radials, are invariably present; and it is the radially situated under- 
basals which may be “present or absent.” In the former case Mr. Miller calls them basals, which 
name he also gives to the sub-radial plates when there are no under-basals. 
This method is doubtless both “ easy ” and “ expressive.” But it unfortunately implies an homology 
between the radially situated plates of one genus (e.a., Poteriocrinus) , and plates which are interradial 
in another (e.g., Platycrinus ) ; and this is utterly opposed to the fundamental principles of morphology, 
not only in the Crinoids, but also in the Echinoderms generally. 
