478 PROCEEDINGS: BOSTON SOCIETY NATURAL HISTORY. 
C. socialis appears to be the most closely allied to the iVmerican 
species. 
Caesira septentrionalis (Traustedt). 
PI. 46, fig. 14-16; PI. 73, fig. 160; text-figs. 6, 7. 
1842. Ascidia conchilega Moller, Naturhist. Tidsskr., vol. 4, p. 95 (non 
MuUer, 1788). 
1883. Molgula seplentrionalis + M. boreas Traustedt, Vidensk. Aleddel. 
Naturhist. For. Kjobenhavn, pp. Ill, 112. 
1891. Molgula septentrionalis + M. boreas Herdman, Journ. Linn. Soc. 
London, Zool., vol. 23, p. 568. 
1892. Molgula septentrionalis Herdman, Proc. and Trans. Liverpool Biol. 
Soc, vol. 6, p. 91. 
1892. Molgula septentrionalis Jacobsohn, Trav. Soc. Nat. St. Petersbourg, 
vol. 23, pt. 2, pp. 9, 13. 
1896. ? Molgula norvegica Kiaer, Norske Nordhavs-Exped., vol. 23, no. 3, 
p. 15, pi. 5, fig. 8-12. 
1901. Molgula septentrionalis Hartmeyer, Meeresfauna Bergens, p. 53, figs. 
19, 20. 
1903. Molgula septentrionalis Hartmeyer, in Romer and Schaudinn, Fauna 
Arctica, vol. 3, p. 152, pi. 4, figs. 7, 8; pi. 7, fig. 12-16; pi. 8, fig. 18. 
1906. Molgula septentrionalis Redikorzew, Trav. Soc. Nat. St. Petersbourg, 
vol. 37, pt. 1, p. 310. 
1907. Molgula septentrionalis Redikorzew, Ann. Mus. Zool. Acad. St. Peters- 
bourg, vol. 11, pp. 129, 151-153. 
1908. Molgula septentrionalis Redikorzew, Trav. Soc. Nat. St. Petersbourg, 
vol. 39, pp. 20, 22. 
1908. Molgula septentrionalis Bjerkan, Tromsoe Mus. Aarshefter, no. 25, 
pp. 56, 57. 
1909. Caesira septentrionalis Hartmej'er, Bronn's Tier-reioh, vol. 3, suppl., 
p. 1324. 
1910. Caesira septentrionalis Hartmeyer, Danmark-Expeditionen, vol. 5, 
p. 229. 
1912. Caesira septentrionalis Hartmeyer, Sitzungsb. Ges. Naturforsch. 
Freunde, 1911, no. 10, p. 439. 
1912. Caesira septentrionalis Hartmej'er, Sitzung.sb. Ges. Naturforsch. 
Freunde, 1912, no. 1, p. 17. 
1912. Caesira septentrionalis Hartmeyer, Vidensk. ]\Ieddel. Naturhist. For. 
Kjobenhavn, vol. 63, p. 264. 
The only specimen in the collection measures about 19 mm. by 
19 mm. by 13.5 mm. None of these diameters, however, corresponds 
to any principal axis of the animal, as it is flattened in a somewhat 
oblique direction. The surface is rough and irregularly incrusted 
with sand and shell fragments (some of considerable size) and bears 
