EASTERN CANADIAN PLANKTON 85 



VII. 



Eastern Canadian Plankton. — The Distribution of the 

 Tomopteridae obtained during the Canadian 

 Fisheries Expedition, 1914-1915. 



BY 



A. G. Huntsman, B.A., M.B., F.K.S.C, 



Biologist to the Biological Board of Canada. 



The Tomopterids form the bulk of the pelagic Annelids of the expedition. Several 

 specimens of species belonging to other groups were obtained, but these were in such 

 poor condition that their identification was not attempted. 



The Tomopterids have proven to be so rare in our material that the method of 

 capture must be considered to a large extent unsuitable for a determination of their 

 •distribution. The four species obtained may be distinguished by means of the fol- 

 lowing table: — 



Key to the species of Tomopteris. 



A^. Rosettes present on the parapodia. Tail present. (Subgenus Johnstonella.) 



B,. Eosettes on the trunk of each of the first two pairs of parapodia and on the 



fins of the remai-nder. T. duccii. 



Bj. Eosettes on the ventral ramus of the first two pairs of parapodia and on all 



the fins. T. catharina. 



Ag. Rosettes absent. TaU lacking. (Subgenus Tomopteris.) 



Ci. Both hyaline and chromophile glands at apex of fin of ventral ramus of 



parapodium. T. septentrionalis. 



Cj. Hyaline gland apical, chromophile gland inferior in fin of ventral ramus 



of parapodium. T. planktonis. 



Tomopteris (Johnstonellai) duccii Rosa. 



1907. Rosa, p. 177. 



1908. Rosa, p. 273. 



The single specimen obtained showed the following characters, which agree -so 

 closely with those of T. duccii, ae described by Rosa, as to leave no doubt of its 

 belonging to that species. 



Length: truiik, 8 mm.; tail, ca. 6 mm. 



Width: the greatest is about 4 mm. 



The prostomium has a convex anterior border. The horns are about 1 mm. long. 

 The first cirri are decidedly shorter than the horns, while the second cirri are 6 mm. 

 long. 



The eyes are distinct, brownish in colour, and elongated longitudinally. The 

 ciliated epaulettes are narrow and tongue-like, extending back considerably behind 

 the cere'bral ganglion. 



♦This article and the following one were completed too late to be included in the report of 

 the expedition (Canadian Fisheries Expedition, 1914-1915, Department of the Naval Service, 

 Ottawa, 1919). For an account of the cruises undertaken, methods used, etc., see the introduc- 

 tion by Dr. Johan Hjort, the leader of the expedition, in that report. 



The stations of C.G.S. " Acadia " and C.G.S. " Princess " are shown in figure 1, the dates 

 for the two cruises of each beingr indicated. The stations taken by C.G.S. " Thirty-three " were 

 all in the Gulf St. Lawrence, while those of the Biological vessel " Prince " were taken in the 

 Bay of Fundy in September of that year (1915). 



