BATHYMET1UCAL DISTRIBUTION. 



The remarks made at the commencement of the section upon Geographical Distribu- 

 tion in regard to the uncertainty of the results, on account of tin- scantiness of our know- 

 ledge, apply with ecpial force to the question of distribution in depth. 



The first table given below shows the range in depth of the specie.-,, genera, and 

 families of Simple Ascidians. The names are arranged systematically, and the extreme 

 limits of depth at which each species has been found are given. 



The depth is not known in the case of Boltenia pachydxvrmati?ia, as t lie two specimens 

 of that species in the collection were presented to the expedition at Wellington, 

 New Zealand. 



(Z ,. CHALL. EXP. — PAhT XVII. — 1882.) 



i; 35 



