A. H. Clark — Study of Recent Crinoids. 61 



Recent 



Apiocrinidse 



Fossil 



Proisocrinus ) ,, 



CaRPENTEROCRINUS \ MlLLERICRINUS 





Apiocrinus 

 Guettardocrinus 





Dadocrinus 





Holocrinits 





Achrochordocrinus 





Phrynocrinidae 



Recent 



Fossil 



Phrynocrinus -,. T 

 at j. None 



Bourgueticrinidse 

 Recent Fossil 



Rhizocrinus 



Rhizocrinus 



Democrinus 

 Jiythocrinus 

 Mon achocrinus 



(*Democrinus) 



Bourgueticrinus 



Mesocrinus 



Balhycrlnus 



Dolichocrinus 



Hycrinus 





Recent 



Holopodidse 



Fossil 



Holopus 



Holopus 





Cotyloderma 

 Cyathidium 



Order Inadunata. 





Plicatocrinidae 



Recent 



Fossil 



Calamocrinus 



Plicatocrinus 



Ptilocrinus 





Hyocrinus 



Gephyrocrinus 



Thalassocrinns 





In the preceding list the genus Democrinus, a widely spread 

 recent type, is included also among the fossil forms. The first 

 species of this genus known was found in a recent breccia in 

 the West Indian island of Guadeloupe ; as the breccia also 

 contained a human skeleton, its age could not have been very 

 great. 



If we compare the recent and fossil generic types in each of 

 the families given above, we at once notice, especially in the 

 two families in which recent and fossil genera are about equally 

 numerous (Pentacrinitida and Bourgueticrinidse) that the two 

 groups diverge in more or less different directions, for each 



