EASTERN CANADIAN PLANKTON 97 



is entirely owing- to the action of currents, since they do not survive in the north from 

 one year to the next, as Apstein has so well shown. In our waters they are excellent 

 indicators of the extent of the Gulf Stream, Their distribution for May-June and 

 July- August is shown in Fig. 1. They were nearer the continental shelf in the later 

 cruise than in the earlier one and to the south than to the north. Their much greater 

 abundance at the southernmost station is very evident, this station providing prac- 

 tically three-quarters of the total number of individuals obtained'. 



The fact that no Thaliacea were obtained from the water over the banks or near 

 the coast indicates the absence, during the period investigated, of any Gulf Stream 

 component within the edge of the continental shelf. That this condition does not 

 always obtain is shown by the two records of Solp'ce from the Bay of Fundy. 



LITFEATUKK. 

 Apsteix, C. 



1894. Die Thaliacea der Plankton-Expedition, T>. Vertheilung d'er Salpen. 



Ergebn. d. Pl.-Exped., Ed. II E. a. B. ' 

 1001. Siilpidfp. Nordisches Plankton, (Bd. II.) Lief, 1. 



1011. Timieata. Bull. Triincstr.. Plankton, 2 me. Partie, p. l.-'-O. 



BiflELOW, II. B. 



1914. Explorations in the Gulf of Maine, July and August, 1912, etc. Bull. Mus. 



Comp. Zool., vol. LVIII, No. 2. 



1915. Exploration of the Coast water between Nova Scotia aud Chesapeake Bay, 



July and August, 1913, etc. Bull. Mus. Comp. Zool., Vol. LIX, No. 4. 

 1917. Explorations of the coast water between Cape Cod and Halifax in 1914 

 and 1915, etc. Bull. Mus. Comp. Zool., Vol. LXI. No. 8. 



BORGERT, A. 



1S94. Die Thaliacea der Plankton-Expedition. C. Vertheilung der Doliolen. 

 Ergebn. d. Pl.-Expd., Bd. II, E. a. C. 



Df.lap, M. and €. 



1905. Notes on the Plankton of Valencia Harbour. Ann. Eep. Fi.sh. Ireland, 

 1902-190S. Pt. II, App. I. 



1006. No'es on the Plankton ot: Valencia Harbour. Fisheries, Ireland, Sci. Invest. ■ 



i9€5, vn. 



Farran, G. p. 



1916. On the Distribution of the Thaliacea and Pyrosoma in Irish waters. Fish- 



eries, Ireland, Sci. Invest. 1906, I. 



IlILE. J. E. W. 



1012. Tunicata. Salpse I. Desmomyaria. Das Ticrreich. 32 Lief. 



Neumann, C. 



1913. Tunicata. Salpa? II. Cyclomyaria et Pyrosomida. Das Tierreich. 40 Lief. 



T9550 — 7 



