Tried to make a sphere and all I got was this bug

PrettyBug.elm

sphereMesh : Int -> Vec3 -> Float -> Mesh
sphereMesh tesselation center radius =
  let normalize = (flip (/)) (toFloat tesselation)
      shift     = (+) -0.5
      scale     = (*) (2 * radius)
      transform = normalize >> shift >> scale
      latitudes  = map transform (map toFloat [0..tesselation])
      longitudes = latitudes
      plotPoint longitude latitude =
        let cosLatitude  = cos (pi * latitude / (toFloat tesselation))
            cosLongitude = cos (2 * pi * longitude / (toFloat tesselation))
            sinLatitude  = sin (pi * latitude / (toFloat tesselation))
            sinLongitude = sin (2 * pi * longitude / toFloat tesselation)
            x = radius * sinLatitude * cosLongitude
            y = radius * sinLatitude * sinLongitude
            z = radius * cosLatitude
        in vec3 x y z
      makeHorizontalPoints longitude =
        map (plotPoint longitude) latitudes
      levels =
        map makeHorizontalPoints longitudes
      connectLevels level1 level2 =
        case level1 of
          [] -> []
          x :: [] -> []
          x1 :: x2 :: xs ->
            case level2 of
              [] -> []
              y :: [] -> []
              y1 :: y2 :: ys ->
                rectangleMesh x1 x2 y1 y2 ++ connectLevels xs ys
      bodyFaces =
        concat <| map2 connectLevels levels (tail levels)
  in bodyFaces