igil] ASCIDIANS FROM THE COASTS OF CANADA. Ill 



ASCIDIANS FROM THE COASTS OF CANADA. 



By a. G. Huntsman, 



Biological Department, University of Toronto. 



(Read 8th April, 1911.) 



The Ascidians of the Marine Biological Stations of Canada. 



The writer has spent a portion of each summer for the last three 

 years at the Marine Stations, in 1908 and 1909 at Departure Bay, 

 British Columbia, and in 1910 at St. Andrews, New Brunswick. As 

 the collections and observations were made during a very short time in 

 each year, little knowledge has been acquired as to the annual and seas- 

 onal variations. However, sufficient has been learned to give some idea 

 of the forms that are available for study at the two stations. 



(A). The Atlantic Station. 



The month of July, 1910 was spent at St. Andrews. Several rocky 

 points were visited repeatedly at low tide and much material obtained. 

 The most favourable places are rocky ledges on precipitous shores, where 

 can be found plenty of flat stones. The lower surfaces of these stones 

 are usually covered with Ascidians. The shores on either side of the 

 station wharf and the shore of Sand Reef Point were the most productive 

 of those that were visited. All the species that were found at low tide, 

 occurred in the dredgings as well, but the majority of them could be 

 obtained more easily and in greater quantity at low tide. 



The facilities at the station and the willing co-operation of the sta- 

 tion staff made possible a large amount of dredging. The writer was 

 especially indebted to Dr. Stafford, the curator of the station, for gen- 

 erous assistance in every way, both in dredging and in other collecting. 

 Dredgings were made at various points (i) in the St. Croix River, (2) 

 in Passamaquoddy Bay, (3) in the approaches to Passamaquoddy Bay 

 (Letite Passages, Quoddy River, Indian River &c.), (4) near L'Etang 

 and (5) out in the Bay of Fundy around and near the Island of Grand 

 Manan. It was only in the last locality that any Ascidians were ob- 

 tained from muddy or sandy bottoms. Nearly everywhere, they were 

 obtainable on hard bottom, stones, shells and gravel. 



Of Compound Ascidians, Amaroucium glabrum, Tetradidemnum 

 [Leptoclinum] alhidum and Holozoa [Distaplia] clavata were generally 



