DISTRIBUTION 



93 



DISTRIBUTION OF THE FLEXIBILIA 



Excluding synonyms, the number of species of the true Flexibilia recog- 

 nized in this work as sufficiently known for definition is 176, belonging to 31 

 genera. In addition to these there are species of 6 genera which have been 

 mentioned in connection with this order, none of which belong to it, but two of 

 which may doubtfully represent transitional forms of some stage. These are: 

 Cleiocrinus, Caleidocrinus, Edriocrinus, Rhopalocrinus, Cydonocrinus and 

 Sycocrinus. Counting only the true Flexibilia, their occurrence may be graph- 

 ically shown by the following tables : 



I. Biologic 



Number of species 



Lecanocrinidae 54 



Sagenocrinidae 20 



Ichthyocrinidae 40 



Taxocrinidae 62 



Total 176 



II. Geologic 

 Number of species by families 



Carboniferous 



Devonian 



Silurian 



Ordovician ..'. 



Totals 



Lecano- 

 crinidae 



9 



5 



40 



54 



Sageno- 

 crinidae 



IO 



O 



IO 



20 



Ichthyo- 

 crinidae 



18 

 IO 

 12 



40 



Taxo- 

 crinidae 



32 



19 



9 



2 



62 



Totals 



69 

 34 



2 



176 



