176 BULLETIN OF THE 



Munier-Chalmas sp., and C. seguenzai Menegh. That they are conge- 

 neric with Forbes's species and with Rhizocrinus I have not the smallest 

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

 is to take precedence over Rhizocrinus Sars. 



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

 ty gebuhrt dem Namen Conocrinus D'Orb. die Prioritiit, wenn gleich 

 die Gattungsdiagnose D'Orbigny's unvollst'andig und theilwise unrich- 

 tig ist." 



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

 crinus thorenti of D'Archiac, but his definition of it was so incomplete 

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

 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 Bourgueticrinus was still a matter of uncertainty. D'Or- 

 bigny f spoke of it as "Genre voisin des Bourgueticrimis, mais sans 

 pieces basales comme les Eugeniacrimis " ; and again, " C'est un Bour- 

 gueticrinus ayant la tige cornpriruee, mais avec une seule serie de pieces 

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

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

 of the Apiocriniolce, which appears on page 2 of his " Histoire Xaturelle 

 des Crino'ides Vivans et Fossiles," and contains the names of both those 

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

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

 Conocrinus, which would belong to a different family altogether. This 

 shows how he had misunderstood its real character 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'Archiac's figures of B. thorenti 

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

 Lastly, the remark that Conocrinus is a Bourgueticrinus with a com- 

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

 itself is described as having a round or compressed stem. 



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

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

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

 only right, therefore, to ignore Conocrinus altogether, and to adopt Saro'l 

 well-known genus Rhizocrinus. 



The differences between Apioerinm and Jfiiiericrimu on the one hand. 

 and Bourgueticrinus and Rhizocrinus on the other, have led Mous. do 



* Lor. cit., p. 212. 



t Prodrome de Taleontologie Stratigraphique Univcrselle, 1850, Tom. II. p 332. 



