127-redshift from de Vaucouleurs et al. (1991).
NGC 5311: S0/a galaxy, at V_opt_ = 2698 +/- 40 km s^-1^, not detected in
our survey (estimated I_HI_ < 2.4 Jy km s^-1^). Detected at Green Bank
(Richter & Huchtmeier 1991), with a considerably higher integrated line
flux, 5.1 Jy km s^-1^, at V = 2645 km s^-1^, with W_50_ = 453 km s^-1^.
The Green Bank profile could in principle be confused with NGC 5313, a
B_T_ 12.8 mag, Sbc type spiral 9.3' due East of NGC 5311, with
V_opt_ = 2597 +/- 44 km s^-1^. Three H I detections of NGC 5313 are
available: one from Green Bank (Peterson 1979) and two from Nancay
(Bottinelli et al. 1982; the present survey); in principle, the Nancay
detections should not be confused by emission from NGC 5311. The H I
profile parameters of NGC 5313 are V = 2551 km s^-1^,
I_HI_ = 9.5 Jy km s^-1^ and W_50_ = 421 km s^-1^. Because the separation
between the two galaxies is comparable to the size of the Green Bank beam,
the "detection" of NGC 5311 could be due to the higher velocities in the
NGC 5313 profile.