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We present observations and models of the kinematics and distribution ofneutral hydrogen (HI) in the superthin galaxy FGC 1440 with an optical axialratio $a/b = 20.4$. Using the Giant Meterwave Radio telescope (GMRT), we imagedthe galaxy with a spectral resolution of 1.7 $\rm kms^{-1}$ and a spatialresolution of $15" \times 13.5"$. We find that FGC 1440 has an asymptoticrotational velocity of 141.8 $\rm kms^{-1}$ . The structure of the HI disc inFGC 1440 is that of a typical thin disc warped along the line of sight, but wecan not rule out the presence of a central thick HI disc. We find that the darkmatter halo in FGC 1440 could be modeled by a pseudo-isothermal (PIS) profilewith $\rm R_{c}/ R_{d} <2$, where $R_{c}$ is the core radius of the PIS haloand $R_{d}$ the exponential stellar disc scale length. We note that in spite ofthe unusually large axial ratio of FGC 1440, the ratio of the rotationalvelocity to stellar vertical velocity dispersion, $\frac{V_{Rot}}{\sigma_{z}}\sim 5 - 8$, which is comparable to other superthins. Interestingly, unlikepreviously studied superthin galaxies which are outliers in the$log_{10}(j_{*}) - log_{10}(M_{*})$ relation for ordinary bulgeless discgalaxies, FGC 1440 is found to comply with the same. The values of $j$ for thestars, gas and the baryons in FGC 1440 are consistent with those of normalspiral galaxies with similar mass.

HI 21 cm observation and mass models of the extremely thin galaxy FGC 1440