26 



SMITHSONIAN MISCELLANEOUS COLLECTIONS 



VOL. 



65 



1. Orals present. Bathymetric Thermal 



range range 



Pentacrinitidse (Calometricke, Pen- 



tacrinitida) 0-1350 36.0-80.0 



? Apiocrinid?e 565-940 36.7-38.1 



Holopodidae 5-120 71.0 



Plicatocrinidse 266-2575 31. 1-43.9 



2. Orals absent. Bathymetric Thermal 



range range 



Pentacrinitidae (Comatulida, except 



Calometridse) 0-2900 28.7-80.0 



Phrynocrinidse 508-703 38.1-40.0 



Bourgueticrinidse 62-2690 29.1-70.75 



Correlated with the presence of a solid plating over the surface 

 of the disk is the presence of large and definite oral plates surround- 

 ing the mouth. 



These orals dwindle in size with the disintegration of the pavement 

 on the surface of the disk, finally, like that pavement, disappearing 

 altogether. 



The disappearance of orals is an example of specialization through 

 the suppression of a fundamental feature, and is quite comparable 

 to the disappearance of the disk plating, with which, in a general 

 way, it is associated. 



Frequency at different depths Frequency at different temperatures 



t •* -\ r •» 



Degrees 

 Fathoms 1 2 Fahrenheit 1 2 



O-IOO 2 2 80-75 ! I 



100-200 2 2 75-70 2 2 



200-300 2 2 70-65 I 2 



3OO-4OO 2 2 65-60 I 2 



4OO-5OO 2 2 60-55 I 2 



500-600 3 3 55-50 I 2 



600-700 3 3 50-45 1 2 



700-800 3 3 45-40 2 . 2 



800-900 3 2 40-35 3 3 



900-1000 3 2 35-30 1 2 



1 000-1500 2 2 30-25 2 



1500-2000 1 2 



2000-3000 1 2 



1 2 



Average depth 707 fathoms 791 fathoms 



Average temperature 52.8 Fahr. 50.7 ° Fahr. 



I. Orals Of different sizes. Bathymetric Thermal 



range range 



Plicatocrinidae 266-2575 31. 1-43.9 



