| The tail length, however, is measured from the base of the uropygium to the tip of the longest pair of rectrices. |
| Seaside Sparrows have a mid-dorsal row of downs in the dorsal tract near the uropygium. |
| The uropygium also, which in the European bird is entirely white, is in our specimen partially variegated with black. |
| The extent of white also on the uropygium varies much in individual examples, sometimes spreading down to the thighs. |
| In some of the families the uropygium is recorded as small in suspiciously close to 25 per cent of the offspring. |
