REPORT ON THE ASTEROIDEA. 



27 



teres. Of these only one species, Pontaster tenuispinus, with its variety platynota, 

 extends into the Abyssal zone. 



Seven species are found in the Abyssal zone, viz., Pontaster for cipatus and 

 its variety echinata, Pontaster mimicus, Pontaster pristinus, Pontaster sub- 

 tuberculatus, Pontaster tenuispinus and its var. platynota, Pontaster trullipes, 

 and Pontaster venustus. Four of these are found in depths greater than 1000 

 fathoms, viz., Pontaster for cipatus and its variety echinata, Pontaster pristinus, 

 Pontaster trullipes, and Pontaster venustus. 



Greatest range of one species : Pontaster venustus, 900 to 2025 fathoms. 



Nature of the Sea-bottom: Five species, viz., Pontaster for cipatus, Pontaster pla- 

 neta, Pontaster pristinus, Pontaster teres, and Pontaster trullipes, are found on 

 Blue mud only, excepting the variety echinata of Pontaster for cipatus, which is 

 found on Globisrerina ooze. Pontaster venustus is found on Globio;erina ooze and 

 Pteropod ooze. Three species are found on Green mud only, viz., Pontaster 

 mimicus, Pontaster oxyacanthus, and Pontaster subtuberculatus. Pontaster 

 tenuispinus and Pontaster limbatus, in the Continental zone, occur on various 

 bottoms. Pontaster hebitus on gravel and stones. 



Chorological Synopsis of the Species. 



1 These two limits are given on the authority of Danielssen and Koren. Den Norske Kordhavs-Expedtion, 

 Zoologi. xi. Asteroidea, Christiania, 1884. 



