510 PROCEEDINGS: BOSTON SOCIETY NATURAL HISTORY. 
1880. Molgula groenlandica Traustedt, Vidensk. Meddel. Naturhist. For. 
Kjobenhavii, p. 425. 
1882. Molgula retortiformis Baird, Rept. U. S. Comm. Fish and Fisheries 
for 1879, pp. 808, 829. 
1883. Molgula groenlandica Traustedt, Vidensk. Meddel. Naturhist. For. 
Kjobenhavn, p. 112. 
1889. Molgula relorliformis McDonald, Rept. U. S. Comm. Fish and P'isheries 
for 1886, p. 858. 
1891. Molgula groenlandica + M. relorliformis + Pera longicollis Herdman, 
Journ. Linn. Soc. London, Zool., vol. 23, pp. 565, 568, 569. 
1901. Molgula relorliformis Kingsley, Proc. Portland Soc. Nat. Hist., vol. 2, 
p. 182. 
1901. Molgula retortiformis Whiteaves, Geol. Survey Canada, pub. no. 722, 
p. 270. 
? 1901. Molgula graphica Ritter, Proc. Washington Acad. Sci., vol. 3, p. 230, 
pi. 27, fig. 6-9. 
1903. Molgula retortiformis Hartmeyer, in Romer and Schaudinn's Fauna 
Arctica, pp. 145, 373, text-figs. 1, 2. 
1905. Molgula retortiformis Bjerkan, Bergens Mus. Aarbog, 1905, no. 5, p. 5. 
1906. Molgula retortiformis Redikorzew, Trav. Soc. Nat. St. Peter.sbourg, 
vol. 37, pt. 1, pp. 308, 309. 
1907. Molgula retortiformis Redikorzew, Ann. Mus. Zool. Acad. St. Peters- 
bourg, vol. 11, pp. 129, 151, 154. 
1907. Molgula retortiformis Redikorzew, Zool. Anzeiger, vol. 31, p. 521. 
1908. Molgula retortiformis Redikorzew, Trav. Soc. Nat. St. P6tersbourg, 
vol. 39, pp. 20, 22. 
1908. Molgula retortiformis Redikorzew, Mem. Acad. Imp. Sci. St. P6ters- 
bourg, ser. 8, cl. phys.-math., vol. 18, no. 11, p. 14, pi. 1, figs. 9, 11, 
text-figs. 3a, 3b. 
1909. Caesira retortiformis Hartmeyer, Bronn's Tier-reich, vol. 3, suppl., 
p. 1324. 
1910. Caesira retortiformis Hartmeyer, Danmark-Expeditionen, vol. 5, p. 229. 
1912. Caesira retortiformis Hartmeyer, Sitzungsb. Ges. Naturforsch. Freimde, 
1912, no, 1, p. 18. 
For a description of the external features of this species Verrill's 
original description is here quoted. It should be emphasized, how- 
ever, that the siphons are very retractile and in preserved specimens 
generally appear only as low papillae, or do not project at all. 
" Body subglobular or more or less oval, generally higher than broad 
and a little compressed laterally, destitute of a disk, though generally 
adhering. The integument is thick and firm, but translucent, usually 
covered, together with the tubes, by various zoophytes, ascidians, 
fragments of shells, etc., which form a coarse, rough, and rather 
