CLARK: BATHYMETRICAL DISTRIBUTION OF CRINOIDS 127 



(1) The average range in depth expressed as a percentage of 

 ^the total range in depth. 



(2) The average depth of habitat expressed as a percentage 

 of the mean depth of habitat. 



(3) The average depth of habitat expressed as a percentage, 

 of the average range in depth. 



Average range 

 in depth ex- 

 pressed in per 

 cent of total 

 range. 



per cent 



Articulata 14 



Pentacrinitid.e 15 



Comatulida 15 



Oligophreata 10 



Comasteridse 18 



Capillasterinse 23 



Comactiniinae 62 



Comasterinse 64 



Zygometridse ! . . . 49 



Himerometridse 54 



*Stephanometrid8e 100 



Mariametridse 53 



Colobometridae 32 



*Tropiometrid8e 100 



Calometridse 42 



Thalassometridae 25 



Ptilometrinae 40 



Thalassometrinae . ... 29 



CharitometridflB 39 



Macrophreata 24 



Antedonidse 19 



Antedoninse 58 . 



Thysanometrinae . ... 61 



Zenometrinse 24 



Peronietrinse 63 



Heliometrinae 39 



Bathymetrinae 64 



Pentametrocrinidae 71 



Atelecrinidae 50 



Pentacrinitida 47 



APIOCRINIDiE 



Phrynocrinid^ 



bourgueticrinid^ 54 



*HoLOPODID^ 100 



Inadunata 41 



Plicatocrinid^ 41 



