<br><ul><li>above: « <i>Chelidon blakistoni</i> » = <i>Delichon dasypus</i> (<a href="https://en.wikipedia.org/wiki/Asian_House_Martin" class="extiw" title="en:Asian House Martin">Asian House Martin</a>)</li>
<li>below: « <i>Chelidon whitelyi</i> » = <i>Delichon urbicum lagopodum</i> (Subspecies of <a href="https://en.wikipedia.org/wiki/Common_House_Martin" class="extiw" title="en:Common House Martin">Common House Martin</a>)</li></ul>
The illustration shows two perched swallow-like birds with black upperparts and white rumps and underparts. The bird higher and to the right has a greyish throat and squarer tail. The upper bird is an Asian House Martin and the lower bird is a Common House Martin.
<bdi><a href="https://en.wikipedia.org/wiki/en:John_Gerrard_Keulemans" class="extiw" title="w:en:John Gerrard Keulemans"><span title="Dutch bird artist (1842-1912)">John Gerrard Keulemans</span></a>
</bdi>
1874
<a rel="nofollow" class="external text" href="https://archive.org/stream/ibis43brit#page/150/mode/2up">The Ibis, ser. 3, vol. 4</a>: <i>On some birds from Hakodadi, in Northern Japan</i> by R Swinhoe. Ibis, 3: 150-.