472 PROCEEDINGS: BOSTON SOCIETY NATURAL HISTORY. 
1894. Molgula Manhattensis Willey, Amphioxus and Ancestry of the Verte- 
brates. New York & London. 
1897. Molgula manhattensis Crampton, Ann. New York Acad. Sci., vol. 10, 
p. 50-57, pis. 4, 5. 
1898. Molgula ynanhattensis Hunter, Journ. Comp. Neurol., vol. 8, p. 202. 
(Notes on peripheral nervous system.) 
1900. Molgula manhattensis Metcalf, Zool. Jahrbiicher, Anat., vol. 13, pp. 
519, 584, 588, pi. 36, figs. 29, 30, 2 text-figs. p. 581. 
1900. Molgula manhattensis Wilson, Amer. NaturaUst, vol. 34, p. 354. 
1900. Molgula manhattensis WiUey, Quart. Journ. Micr. Sci., vol. 44, p. 141- 
160, pi. 9. 
1903. Molgula (Bostrichobranchus) manhattensis Bancroft and Esterly, 
Univ. of California Pubhcations, Zool., vol. 1, p. 105. 
1902. Molgula manhattensis Hunter, Anat. Anz., vol. 21, p. 241-243, 3 text- 
figs. (Structure of heart.) Abstracts in Journ. Roy. Mic. Soc, 
1902, p. 548; iZool. Jahrb., 1902. 
1903. Molgula manhattensis Hunter, Amer. Journ. Physiol., vol. 10, p. 1-27. 
(Notes on heart action.) 
1909. Caesira manhattensis Hartmeyer, Bronn's Tier-reich, vol. 3, suppl.. 
p. 1323. 
1912. Caesira manhattensis Hartmeyer, Sitzungsb. Ges. Naturforsch. Freunde, 
1912, no. 1, p. 14. 
1912. Caesira manhattensis Hartmeyer, Denkschr. K. Akad. Wiss. Wien, 
cl. math.-nat., vol. 88, p. 209. 
Probably not Molgula manhattensis Kingsley (1901, p. 182). 
Body normally nearly globular except for some degree of lateral 
compression. Siphons diverging and usually more or less curved, 
originating from the dorsal surface a little way apart or, less often, 
quite close together. The atrial siphon is tapering and may equal 
half the body diameter in length; it has a square aperture. The 
branchial siphon is shorter, stouter and more truncate, and has a 
six-lobed aperture. Attachment of body frequently by a rather small 
area on the left ventral surface, but several or many individuals 
often grow together in a cluster, and the position of the area of 
attachment as well as its extent, is very variable. 
Test firm, tough, and moderately thick, with a finely but irregularly 
roughened surface. This roughness commonly develops on or near 
the bases of the siphons into more or less noticeable papillae, and on 
various parts of the body into an irregular coat of short, uneven, hair- 
like processes, which would not be particularly conspicuous were it 
not that they generally serve to catch and attach sand grains, shell 
fragments, bits of eel-grass and other debris, the fragments being 
