GEOGRAPHICAL DISTRIBUTION. 



We know as yet very little as to the Geographical Distribution of the Tunicata — far 

 too little to make generalisations of much value. Still it will be useful to future investi- 

 gators to tabulate what has been already determined, even if in many cases it shows 

 merely negative results. But it must be borne clearly in mind, when examining the 

 following statements, that only a very small area of the sea bottom was examined al 

 each Station, and that Tunicates might very possibly be abundant in a locality from which 

 none are here recorded. 



I have divided the track of the Challenger round the world into a series of comparat ively 

 short stages, so as to show roughly the localities between which the different observing 

 Stations lie. These stages are arranged in the order in which they were traversed by the 

 expedition, and consequently the Stations are in chronological order, and the lists of 

 species occur in the order in which they were collected. The chief objects of this arrange- 

 me it are to show — (1), the approximate positions of the Stations at which Tunicates were 

 oh lined, and (2), the list of species from each Station. 



Between England and the Canary Islands the following Tunicate was dredged : — 

 Off Gomera, the Canary Islands, 10th February 1873 ; depth, 75 fathoms. 

 Ciona jl&mingi. 



Between the Canary Islands and the West Indies no Tunicata were obtained. 



Between the West Indies and Halifax the following Tunicata were obtained : — 

 Off Bermuda, June 1873 ; in shallow water. 

 Ascidia nigra. 

 EctcinKscidta turb'uiata. 

 Clavelina oblonga. 

 Station 44, May 2, 1873; Lit. 37° 25' N., long. 71° 40' W.; depth, 1700 

 fathoms; bottom temperature, l° - 7 O; bottom, grey ooze. 

 Culeolus perlatus. 

 Station 48, May 8, 1873; lat. 43 2' X., long. 04 2' W.; depth, 51 fathoms; 

 bottom, rock. 



Boltenia elegans. 1 



The label in the bottle is marked Le Have Bank, Xova Scotia, 75 fathoms. 



