176 BULLETIN OF THE 



Municr-Chalmas sp., and C. seguejizai Menegh. That they are conge- 

 neric with Forbes's species and with Rldzocruius I Imve not the smallest 

 doubt ; and the question therefore arises whether Conocrimis D'Orbigny 

 is to take precedence over lihizocrimis Sars. 



On this subject Prof. Zittel remarks, " Nach den Rcgeln der Priori- 

 tilt gebiihrt dem Nanien Conocrinus D'Orb. die Prioritiit, wcnn gleicli 

 die Gattungsdiaguose D'Orbigny's uuvollstandig uud tlieilwise unrich- 

 tig ist." 



The type on which D'Orbigny founded Conocrinus was the Bourgueti- 

 crimis tlioreiiti of D'Archiac,. but his definition of it was so incomplete 

 and so incorrect that, even supposing Sars had not defined Rldzocrinus 

 as elaborately as he did, I should not admit Conocrinus as a valid genus 

 until it had been re-defined. Liitken * remarked, in 18G4, that its dis- 

 tinctness from Bounjiicticrinus was still a matter of uncertainty. D'Or- 

 bignyf spoke of it as "Genre voisin des Bonrcjueticrinus, mais sans 

 pieces basalcs comme \e^ Eugeniacrinits'''' ; and again, " C'est un Bour- 

 gueticrimis ayant la tige comprimee, mais avec une seule scrie de pieces 

 basales." If he considered it as near Boiirgudicrinus and as resembling 

 Eugeniacrinus, why did he omit it altogether from the tabular scheme 

 of the Apiocrinidce, which appears on page 2 of his " Ilistoire Naturelle 

 des Crinoides Vivans et Fossiles," and contains the names of both those 

 genera 1 It would seem from his reference to the absence of any tertiary 

 species of Bourgueticrinus on page 96 that he included them all in 

 Conocrimis, which would belong to a different family altogQther. This 

 shows how he had misunderstood its real chai-acter and affinities, and as 

 a matter of fact his description of it as having no basals is entirely 

 incorrect. They are visible enough in D'Ai-chiac's figures of B. thorenti 

 (the type-species of Conocrinus), and in other closely allied species. 

 Lastly, the remark tliat Conocrinus is a Baurgueticrinus with a com- 

 pressed stem, is worthless as a generic description, when the latter genus 

 itself is described as having a round or comj^rcssed stem. 



The differences between the two types are of an entirely different char- 

 acter from those mentioned by D'Orbigny, which would be absolutely 

 unintelligiVile in the absence of figures or of original specimens. I feel it 

 only riglit, therefore, to ignore Conocrinus altogether, and to ado])t Sars's 

 well-known genus Ilhizocrinns. 



The diff'erences between Ajjiocrimis and Millericrinus on the one hand, 

 and Bourgucticrinus and Uhizocrinus on the other, have led Mons. de 



* Loc. cit., p. 212. 



t Prodrome de Paleontologie Stratigraplu(iue Universelle, 1850, Tom. II. p 332. 



