Type specimens of birds in the Natural History Museum, University of Oslo, Norway Author Johannessen, Lars Erik Natural History Museum, University of Oslo, PO Box 1172 Blindern, NO- 0318 Oslo, Norway Author Lifjeld, Jan T. 0000-0002-9172-9985 Natural History Museum, University of Oslo, PO Box 1172 Blindern, NO- 0318 Oslo, Norway & j. t. lifjeld @ nhm. uio. no; https: // orcid. org / 0000 - 0002 - 9172 - 9985 j.t.lifjeld@nhm.uio.no text Zootaxa 2022 2022-06-09 5150 4 451 486 journal article 69152 10.11646/zootaxa.5150.4.1 9f4f4dd6-92eb-4946-b5a4-2fe994807894 1175-5326 6626759 7A36C3D5-765A-43E8-BA3F-68C51253B3A0 Psephotus dissimilis Collett, 1898 Proceedings of the General Meetings for Scientific Business of the Zoological Society of London, 1898 (3): 356–357. Current name: Psephotellus dissimilis ( Collett, 1898 ) Syntype NHMO-BI-64125 [I022711]; Study skin; F; Knut Dahl (1180), 12 May 1895 ; Australia : Mary River , Arnhem Land ; 13.700° S 132.000° E ; 9a. Syntype NHMO-BI-85843; Mounted ; F; Knut Dahl (1167), 12 May 1895 ; Australia : Mary River , Arnhem Land ; 13.700° S 132.000° E ; 9b. Remarks: Collett (1898) based the original description on four specimens collected by Knut Dahl, without specifying any holotype . Two of the specimens, a male and a female, were sent to the Australian collector Gregory Macalister Mathews ( Mathews 1913 ; 1942 ; Greenway 1978 ). Later, they must have come to the Rothschild collection at Tring, London, before they ended up in the American Museum of Natural History in 1932 when a large part of the Rothschild collection was sold to the AMNH ( Greenway 1973 ; 1978 ). These specimens are not mentioned in any of Hartert’s publications on the types in the Mathews collection ( Hartert 1929 ; 1931a ; b), but none of these include the order of the parrots (Psittaci; currently Psittaciformes ). Presumably, this order was planned to have been covered in a later publication, which never came out, probably due either to the sale of the collection to the AMNH or the death of Hartert in 1933. The specimens are currently in the AMNH with registration numbers AMNH 623431 (M) and AMNH 623432 (F) ( Greenway 1978 ; American Museum of Natural History 2021 ; Paul R. Sweet, pers. comm.). The original description mentions two fully grown birds with rather worn plumage, a male and a female, and two younger and freshly moulted females ( Collett 1898 ). Both NHMO specimens are females but there is no indication of their age, which is also the case for the female specimen in AMNH ( Greenway 1978 ; American Museum of Natural History 2021 ; Paul R. Sweet, pers. comm.). However, the plumages of the two NHMO specimens appear relatively fresh and are also very similar in the two specimens , while that of the AMNH female appears worn, based on photos provided by Paul R. Sweet, AMNH. It, therefore, seems safe to conclude that the NHMO specimens are the two younger females, and the AMNH female is the fully grown female, as described by Collett (1898) . Based on the collection date of the two AMNH specimens ( 9 May 1895 ), and a list of specimens collected by Dahl during his Australia expedition (unpublished), it is also evident that the original collector’s number must be 1181 and 1182 for the female and male, respectively . The original labels, written by the collector, are present on both specimens ( Figure 2c and 2e ), and NHMO-BI-64125 also has another label ( Figure 2d ) which has been added at the NHMO, probably shortly after accessioning into the collection. The locality was given as ‘Mary River, Arnhem Land’ by Collett, but only ‘Mary River’ on the original labels. In addition to referring to a rather large area, this locality name is probably also somewhat misleading, as it indicates that the birds were collected along the river. However, in his diary, Dahl noted that they stayed at ‘Mt. Gardiner’ in the period 6–14 May, and according to his travelogue ( Dahl 1924 ; 1926 ) they stayed in an area covered by ‘small hills composed of enormous granite boulders’ , some miles ( 7–8 miles , according to his diary) west of the old Eureka mine (approximately 40 km NE of Pine Creek). While Mt. Gardiner ( 13.738° S 132.233° E ) on current maps (e.g. https://mapcarta.com/) is located 5–6 miles to the southeast of the abandoned Eureka mine (Eureka Creek Prospect, 13.687° S 132.168° E ; Digital Atlas Pty Limited 2021 ), we consider an area dominated by numerous, small hilly outcrops about 10–12 miles west of the Eureka mine to be the most likely type locality for this taxon. This is based both on its location, being in general accordance with Dahl’s notes (of which especially the cardinal direction indicated can be assumed to be reliable), and the topographic appearance of this area, which fits very well with both notes and images in Dahl’s diary and travelogue. Finally, this is also in concordance with Collett’s (1898) comment that ‘This Parrot was met with here and there in small flocks in Arnhem Land, particularly between Pine Creek and Catherine River’ , i.e. even further to the southwest from the upper reaches of Mary River. Collett also described a new mammal species, Pseudochirus dahlii Collett, 1895 (currently Petropseudes dahli ( Collett, 1895 )) , from specimens collected by Dahl during his stay at ‘Mt. Gardiner’ ( Wiig & Bachmann 2013 ), and a specimen sent by Collett to the British Museum (Natural History) in 1897 subsequently became the holotype of Petrogale brachyotis signata Thomas, 1926 (currently Petrogale brachyotis Gould, 1841 ).