248 THE VOYAGE OF H.M.S. CHALLENGER. 
really belonged to Conocrinus. But as he did not place the latter type among the 
Apiocrinidee together with Bourgueticrinus and Bugeniacrinus, it would seem that he had 
either abandoned it altogether, or else entirely misunderstood its real character and 
affinities ; and in the absence of figures or original specimens his account of it would be 
absolutely unintelligible. 
Rhizocrinus was first described by Sars in 1864,’ and more fully in 1868°; and 
though he was led to consider the anchylosed basals as a top stem-joint, this error was 
corrected by Pourtalés and myself before a fresh diagnosis of Conocrinus was given by 
de Loriol.? This indeed was only provisional, in default of better knowledge, and owing 
to Meneghini’s failure to find the interbasal sutures in a section through the lower part of 
the calyx,‘ just as in a recent Rhizocrinus or Bathycrinus (Pl. VIla. fig. 13), de Loriol 
was led to consider it probable that the basals “ n’existent pas et sont intimement soudées, 
de maniére 4 former comme une seule piece centro-dorsale.” He thus fell into exactly 
the same error as had been made by Sars and Ludwig respecting the recent Rhizocrinus 
lofotensis. Zittel,? however, who had satisfied himself regarding the presence of inter- 
basal sutures in Conocrinus pyriformis, recognised the identity of this genus with Rhizo- 
crinus, but did not adopt the latter name on the ground that ‘Nach den Regeln der 
Prioritiit gebiihrt dem Namen Conocrinus, d’Orb. die Prioritit, wenn gleich die Gattungs- 
diagnose @’Orbigny’s unyollstiindig und theilweise unrichtig ist.” 
It seems to me, however, that this is stretching the rules of priority to the widest 
possible limit, or even beyond it ; and that definitions which are incorrect, meaningless, 
and altogether incomplete have no claim whatever to recognition. Liitken remarked in 
1864 that the distinction of Conocrinus from Bourgueticrinus was still a matter of 
uncertainty ; while d’Orbigny’s own countrymen Hébert and Munier-Chalmas did not 
adopt his generic name for the new type which they described as Bourgueticrinus suesst ; 
and although it was subsequently referred by de Loriol to Conocrinus, and carefully 
described, the genus Rhizocrinus had meanwhile become thoroughly well established and 
universally recognised by zoologists. 
Both Sars and de Loriol were in error as to the composition of the calyx in this type ; 
and a correct definition of Conocrinus was not given until the publication of Zittel’s 
Paleontology in 1879; while even as early as 1868,° and subsequently more fully in 
1874,’ Pourtalés had correctly pointed out the characteristic features of Sars’s genus 
Rhizocrinus, especially as regards the presence of basals, which had been supposed to be 
either absent altogether, or else modified into a kind of rosette. According to Sars* 
“Ce qui est remarquable et characteristique pour la tige du Rhizocrinus, c’est son sommet 
1 Forhandl. Vidensk. Selsk., p. 127. 2 Crinoides vivants, pp. 38, 39. 
3 Swiss Crinoids, p. 191. * Loc. cit., p. 50. 
5 Paleeontologie, p. 392. & Bull. Mus. Comp. Zodl., vol. i., No. 7, p. 129. 
7 Ill. Cat. Mus. Comp. Zodl., No. 8, pp. 27, 28. * Crinoides vivants, p. 4. 
