A history of the British hydroid zoophytes. By Thomas Hincks.

1

American hydroids ... By Charles Cleveland Nutting ...

pt.2

American hydroids ... By Charles Cleveland Nutting ...

pt.1

A history of the British hydroid zoophytes. By Thomas Hincks.

2

Special bulletin / Smithsonian Institution, United States National Museum.

no. 2 (1895)

Report on the Hydroida : collected during the exploration of the Gulf Stream by L. F. de Pourtalès, assistant United States Coast Survey / by Geo. J. Allman, M.D., LL.D., ...

v.5:no.2 (1877)

The hydroids / by Samuel F. Clarke.

v.35:no.1 (1907)