VAX NAME: COMPOUND ASCIDIANS. 411 
1S79. Amanicciion ylahrum Verrill, Preliminary Check-list of Marine Inverte- 
lirates, p. 27. 
1S91. Ainaroeciuni glabruni Herdman, Journ. Linn. Soc. London, Zool., 
vol. 23, p. 628 (listed under heading " unrecognizable Polyclinidae"). 
1901. Amaroucium glahrum Kingsley, Proc. Port-land Soc. Nat. Hist., vol. 2, 
pt. 5, p. 183. 
1901. Amarnucium glahrum Whiteaves, Catalogue of Marine Invertebrata, 
p. 200. 
1909. Amaroucium glahrum Hartmeyer, Bronn's Tier-reich, vol. 3, .suppl., 
p. 1477 (listed as uncertain species). 
The synonvmy of A. transluciduni Ritter, 11)01, which as stated 
below (p. 415) is closely allied to, if really distinct from this species, is as 
follows : 
1892. Circinalium pachydermatinum (part.) Jacobsohn, Trav. Soc. Nat. St. 
Petersbourg, vol. 23, pt. 2, pp. 158, 159. 
1901. Amaroucium translucidum Ritter, Proc. Washington Acad. Sci., vol. 
3, p. 249, pi. 30, figs. 29, 30. 
1903. Amaroucium translucidum Hartmeyer, in Romer and Schaudinn, Fauna 
Arctica, vol. 3, p. 326, fig. 40-42, pi. 6, figs. S, 9; pi. 13, fig. 10-12. 
1906. Amaroucium translucidum Redikorzew, in Derjugin, Die murmansche 
biologische Station, Trav. Soc. Nat. St. Petersbourg, vol. 37, p. 155. 
1906. Amaroucium translucidum. Redikorzew, Trav. Soc. Nat. St. Peters- 
bourg, vol. 37, pp. 309, 310, 366. 
1907. Amaroucium translucidum Redikorzew, Ann. Mus. Zool. Acad. Imp. 
Sci. St. Petersbourg, vol. 11, pp. 149, 151, 153, 154. 
1907. Amaroucium translucidum Redikorzew, Zool. Anzeiger, vol. 31, p. 522. 
1908. A maroucium translucidum Redikorzew, Trav. Soc. Nat. St. Petersbourg, 
vol. 39, pp. 20, 23. 
1908. Amaroucium translucidum Redikorzew, M6m. Acad. Imp. Sci. St. 
Petersbourg, ser. 8, cl. phys.-math., vol. 18, no. 11, p. 46. 
1909. Amaroucium, translucidum Hartmeyer, Bronn's Tierreich, vol. 3, 
suppl., p. 1467. 
Ordinarily, colonies of Amaroucium glahrum form rounded or more 
or less fiat-topped heads, 10 to 20 mm. in height, usually with 
rather abrupt sides which contract to a narrow base or short peduncle. 
A colony may consist of but one or several such heads, which, when 
small, generally consist of a single system containing rather few irregu- 
larly placed zooids surrounding a single cloacal aperture. Larger 
and broader heads may contain several systems, though in preserved 
specimens their number and limits are rarely discernible. The amount 
of common test substance as compared with the bulk and niunber of 
the zooids is generally large, so that the zooids are commonly well 
