1879.] On the Comatulse of the 6t Challenger" Expedition. 383 



they never, at any time, participated in the rhythmic swing or feeding 

 movements of these last. 



Gentle pressure on the anus or the sexual organs excites or inhibits 

 the swimmerets, according as they are already at rest or in motion, 

 and leads, where possible, to a folding of the abdomen. The feeding 

 and preening movements are also, as a rule, brought to a complete 

 standstill by slight irritation of the anus, the after movements being 

 in all cases more violent. So long as the nervous connexion with the 

 tail-fin remained intact, the swimmerets can be excited to considerable 

 activity by touching this region, but when this connexion is destroyed, 

 it is with difficulty they are made to move at all. 



The experiments, of which the above is a brief and preliminary 

 account, were carried on at the Physiological Laboratory, Cambridge. 



II. " Preliminary Report upon the Comatulce of the ' Challenger ' 

 Expedition." By P. Herbert Carpenter, M.A., Assistant 

 Master at Eton College. Communicated by Sir Wyville 

 Thomson, F.R.S. Received February 18, 1879. Published 

 by permission of the Lords Commissioners of the Treasury. 



The collection of Oomahdce made by the staff of the " Challenger " 

 includes specimens from 45 different localities, but few of which are 

 deep-water stations. Comatulce were only obtained seven times from 

 depths exceeding 1,000 fathoms, namely at: — 



Station. Depth. Station. 



205 1,050 fathoms 158 



218 1,070 „ 160 

 175 1,350 „ 244 



147 1,600 



At lesser depths, 200 — 1,000 fathoms, Comatulce were met with at 

 13 stations ; but by far the greatest number both of species and of 

 individuals were dredged at depths much less than 200 fathoms, and 

 often less than 20 fathoms, at 26 widely distant stations. 



Depth. 

 1,800 fathoms. 

 2,600 „ 

 2,900 „ 



No. 



Station. 



Locality. 



Depth in 

 fathoms. 



Antedon. 



Actinometra. 



_g 



o 

 o 



-s 



c3 



S 

 O 

 u 



Opliiocriniis. 



1 



48 





51 



2 









2 







10—80 





1 







3 



122 





350 



1 









4 







7—20 



1 



2 







