572 



THE VOYAGE OF H.M.S. CHALLENGER. 



Table showing the Species of Comatulee which occur in the Abyssal Zone. 



The characteristic abyssal species of Antedon thus belong to two very distinct types. — 



(1) That with the bases of the rays flattened laterally and plated ambulacra. It is 

 rarely represented above 100 fathoms and ranges downward to 1600 fathoms. Eight of 

 the ten abyssal species are simple forms with but ten arms. This type is represented 

 in the fossil state by Antedon costata (the Solanocrinus costatus of Goldfuss) from 

 the White Jura (e) of Southern Germany, as has been already indicated on p. 101. 



(2) Delicate ten-armed species allied to Antedon tenella of the Subarctic region, which 

 has a range in depth of 50 to 740 fathoms. The only Antedon found below 1600 



