Ninth Street station

In the book "The Hudson & Manhattan Railroad Revisited" the author, Paul Carleton, has a map of the 9th Street station on page 53 showing a short section of tunnel built going east under 9th street. This tunnel is perpendicular to the tunnel under 6th Ave which ended up at the present 33rd (really 32nd) St station. Where was the 9th Street extension supposed to go?

That's the extension over to the IRT station at Astor Place.
Take a look at the map in "Section 2 Construction Description" at http://www.hudsoncity.net/tubes/gatewaytubepage.html

Communipaw,

Thanks for the link! I never knew about the plan to link with the IRT at Astor Pl!