Tunic a fa. 199 



or even M-lien (lec(jiiii)o,sin!^ lie found floatinir on the surface. The 

 specimens collected on 16th December, 1899, and by Dr. Donald in 

 the Erebus and Terror Gulf, floating on the surface, were, doubtless, 

 detached and probably decaying masses from colonies at the bottom. 

 The central parts of the colonies are occupied by very loose test, 

 mucli vacuolated, and penetrated by canals in which run ectodermal 

 processes or stolons from the ascidiozooids. These processes end in 

 dilated bulbs, and have numerous btids in the test around them, 

 recalling the condition in the stalk or basal part of some species of 

 the closely allied genus Colella. 



THALIACEA. 

 Family SALPIDAE. 



Salpa runcinata-fusiformis, Chamisso — Cuvier. 



This was the only species of pelagic Tunicate in the collection, 

 and all the specimens belong to the aggregated or chain form. They 

 were found as follows : — 



" Cape Adare, 5th April, 1899, ten specimens." These are all 

 small, the largest being 2 cm. in length. 



" Cape Adare, 9th April, 1899," thirty specimens, of sizes up to 

 4 cm. in length. 



" Cape Adare, 30th April, 1899," forty specimens, " found on the 

 surface, and on beach ; temperature of water 28 • 6° Fahr." 



"Cape Adare, 10th May, 1899, on surface and along beach, 

 temperature of water 28^ Fahr." Fifty specimens from 2 • 5 to 3*5 

 cm. long. 



Some of the specimens show lines of minute denticles projecting 

 from the surface of the test. This is a species that seems to be 

 abundant in the Antarctic. The ' Challenger ' expedition obtained it 

 both in tropical seas (north of the Admiralty Islands, under the 

 equator) and also in several localities far south, such as " off Prince 

 Edward Island," " near Heard Island," and at " Station 152, Antarctic 

 Ocean, lat. 60° 52' S., long. 80° 20' E., surf. temp. 34° 5' Fahr. ; 

 about 160 specimens of the aggregated form, many of them large." 

 But the present is probably its furthest south record. Apparently 

 the southern forms are usually larger than those found in warmer 

 seas. 



