436 PROCEEDINGS OF THE NATIONAL MUSEUM. VOL. XXXIV. 
asteria, monobrachius for macrobrachius, and radiata and alarchianus 
for pectinata and aldrichianus are not quite so evident. 
More or less confusion has arisen from the use by Professor von 
Graff and others of a number of manuscript names furnished by 
Prof. C. Semper and Dr. P. H. Carpenter, as many of the species to 
which they refer have never been described, or have been described 
under different names. The manuscript names published by Doctor 
Liitken and by Dujardin and Hupé seem to have entirely escaped the — 
notice of subsequent workers. In the case of a nomen nudum, the 
name is referred to the first author who published it; if the same 
species to which the original name referred was subsequently described 
under that name, the.name of the species is credited to the one who 
first described it; but the first reference to it as a nomen nudum is 
cited. Many names ran for years as nomina nuda before being 
definitely attached to any species, while a large amount of anatomical 
work has’ been done on species mentioned by name, but never properly 
described. Such a case is that of Actinometra nigra, the anatomy of 
which was worked out in part, and a number of figures of arm sec- 
tions and other features, interesting from an anatomical, but wholly 
worthless from a systematic point of view, published. Finally, after 
twelve years from the first appearance of the name, a meager sum- 
mary of its specific characters is found, but no good description has ever 
been published. While anatomical characters constitute an ‘* indica- 
tion” in the strict sense of the term, they are largely worthless, so far 
as our present knowledge goes, for correct specific determination; but, 
as names based on them are not nomina nuda, they must be considered 
in the same way as a description, and these names must receive the same 
treatment as names accompanied by a satisfactory diagnosis. 
In regard to the names published by Prof. F. J. Bell in 1882 — 
accompanied by certain so-called specific formule, the formule must 
be taken as constituting descriptions, however non-diagnostic they may 
be, and Professor Bell had no right to change certain of the names when, 
two years later, he published detailed descriptions. The same applies 
to the formulas published by Doctor Carpenter in footnotes in his 
report on the Challenger stalked crinoids; he evidently supposed them 
to be diagnostic, and it becomes necessary to date many of his free 
crinoids from these formulas given in 1884, instead of from the detailed 
descriptions published four years later. - 
In addition to specific names applied to recent species, in the genera 
Eudiocrinus, Atelecrinus, Comatula, Antedon, and Actinometra those 
applied to fossil species have also been included, to guard against the 
possibility of future writers using these names over again. These are 
indicated by adagger (+); a dagger preceding a generic name indicates 
that all the included species are fossil. | 
The present paper is in no way a synonymy of the group, and so 
remarks under the respective names are avoided so far as possible; but 
