19 1 1] ascidians from the coasts of canada. 1 37 



Notes on the Species of the Atlantic Coast. 



With the exception of the compound forms, which have been re- 

 cently thoroughly treated by Dr. Van Name (Proc. Bost. Soc. N. H., 

 vol. 34, No. II, 1910), the species of the East Coast have for the most 

 part been only imperfectly described. It will be necessary therefore 

 to give an account of the anatomy of many of the species. It has been 

 very diflficult in many cases to refer, with much certainty, my specimens 

 to the species that have been described from this coast, owing to the im- 

 perfect descriptions of the older authors. As many of the specimens 

 have been obtained from or near the localities which gave the types of 

 the species, the identifications should have a greater probability of being 

 correct. Dr. Van Name, who is at present engaged in work on the simple 

 Ascidians of this coast, has been most kind in giving me help in the iden- 

 tification of my specimens with Verrill's species. He has corrected some 

 errors into which I had fallen and confirmed some of my surmises. 



Aplidiiim spitzbergense Hartmeyer, Fauna Arctica, Bd. 3, Lf.2,p.34i. 



A single capitate colony was obtained in Long Island Bay, Grand 

 Manan, in about 8 fathoms. This species has been previously reported 

 only from Spitzbergen. The agreement with Hartmeyer's description 

 seem.s, however, to be perfect. 



The colony is 15 mm. by 10 mm., with a thick stalk 8 mm. long. 

 The test contains very numerous sand-grains. 



The zooids are about 2.5 mm. long. Oral aperture 6-lobed. Atrial 

 aperture round, at the end of a short tubular siphon, placed opposite 

 the interval between the first and second stigmatic rows. A long atrial 

 languet is present a short distance in front of the siphon. Four stigmatic 

 rows. Four gastric folds. Abdomen and postabdomen together are slightly 

 longer than the pharynx. Ovary small and no embryos present. 



Another colony, not capitate, 20 mm. long, 9 mm. wide and 6 mm. 

 thick, seems to be referable to the same species. There are much 

 longer and narrower zooids with the ovaries well developed, embryos 

 in the peripharyngeal cavity, and the postabdomen nearly equal in 

 length to the thorax and abdomen together. The colour of this colony, 

 when living, was decidedly greenish. 



This second colony was obtained off Long Island, Grand Manan, in 

 about 35 fathoms shelly and muddy. 



Of the characters which distinguish Aplidiiim from Amaroucium 

 the only one possessed by this second colony is the small number of 

 stigmatic rows. It might be best to place it in the genus Amaroucium, 

 near A. diaphanum (v. Drasche). 



