Type Specimens Of Birds In The American Museum Of Natural History Part 8. Passeriformes: Author Pachycephalidae Author Aegithalidae Author Remizidae Author Paridae Author Sittidae Author Neosittidae Author Certhiidae Author Rhabdornithidae Author Climacteridae Author Dicaeidae Author Pardalotidae Author Nectariniidae, And Author Lecroy, Mary Division of Vertebrate Zoology (Ornithology) American Museum of Natural History (lecroy @ amnh. org) text Bulletin of the American Museum of Natural History 2010 2010-06-03 2010 333 1 178 journal article 0003-0090 Aegithaliscus iouschistos obscuratus Mayr Aegithaliscus iouschistos obscuratus Mayr in Stanford and Mayr, 1940: 705 (Chengou Forks, 7600 ft. , 30 miles west of Wenchwan, Sungpan district, northern Szechwan). Now Aegithalos bonvaloti obscuratus ( Mayr, 1940 ) . See Eck and Martens, 2006: 5–7 , Dickinson et al., 2006a: 69 , and Harrap, 2008a: 98 . HOLOTYPE : AMNH 423917 , adult male, collected at Chengou Forks , 30 miles west of Wenchwan , 7600 ft , 31.29N , 103.40E (Times Atlas), western Sichuan ( 5 Szechwan) Province , China , on 4 December 1934 , by T. Donald Carter (no. c 332), on the Sage West China Expedition. COMMENTS: The AMNH number of the holotype was given in the original description. Vaurie (1959: 469) noted that Wenchwan is in western Sichuan rather than the Sungpan district of northern Sichuan . Cheng (1987: 500) gave the current name of Wenchwan as Maowen. Mayr did not mention specimens other than the type in the original description; however, Birckhead (1937) reported on the birds collected on the Sage Expedition and noted three adult males collected at Chengou Forks, all of which would have been available to Mayr. The two paratypes are: AMNH 423916 , male collected on 28 November 1934 (no. c 293), and AMNH 423918 , male collected on 4 December 1934 (no. c 333). Often considered a subspecies of A. niveogularis , obscuratus was considered a subspecies of allospecific A. bonvaloti by Harrap (2008a: 98) .