Collecting dates & localities by mysterious J. J. Menden in chronological order
1927-10-06 – Java (Jawa Barat) – Collocalia francica javensis Stresemann, 1931
1927-10-09 – Java (Jawa Barat) – Ninox scutulata javanensis Stresemann, 1928
1927-12-08 – Java (Jawa Timur) – Pachycephala pectoralis javana Hartert, 1928
1928-05-23 – Java (Jawa Barat) – Zosterops palpebrosa sindorensis Siebers, 1929
1928-05-31 – Java (Jawa Barat) – Arborophila javanica bartelsi Siebers, 1929
1929-10-18 – Java (Jawa Barat) – Rhinomyias olivacea javanensis Neumann, 1941
1929-12-17 – Java (Jawa Barat) – Cyanoderma melanothorax mendeni Neumann, 1935
[1930]
1931-02-23 – Java (Jawa Barat) – Callosciurus nigrovittatus phoenicurus Sody, 1949
1931-07-11 – Java (Jawa Barat) – Petaurista petaurista interceptio Sody, 1949
[1932, 1933]
1934-01-10 – Pagai Utara – Hemiprocne comata stresemanni Neumann, 1937
1934-06-03 – Sumatra (Palembang) – Rattus rattus palembang Tate & Archbold, 1935
1934-06-09 – Sumatra (Palembang) – Pithecus femoralis fluviatilis Chasen, 1940
1934-08-02 – Sumatra (Lampung) – Callosciurus notatus kalianda Sody, 1949
1935-01-16 – Pagai Utara – Rattus rattus auroreus Sody, 1941
1935-01-18 – Pagai Utara – Chiropodomys karlkoopmani Musser, 1979
1935-01-19 – Pagai Utara – Rhinolophus pagi Tate & Archbold, 1939
1935-01-23 – Pagai Utara – Lariscus insignis auroreus Sody, 1949
1935-01-31 – Pagai Utara – Hipposideros breviceps Tate, 1941
1935-06-16 – Kalimantan (Sampit, S Borneo) – Lonchura atricapilla obscura Restall, 1995
1935-06-17 – Kalimantan (Sampit, SW Borneo) – Callosciurus notatus vinocastaneus Sody, 1949
1935-07-02 – Kalimantan (Sampit, S Borneo) – Anorrhinus galeritus minor Mayr, 1938
1935-11-01 – Kalimantan (Riam, SW Borneo) – Rattus whiteheadi coritzae Sody, 1941
1935-11-04 – Kalimantan (Riam, SW Borneo) – Rattus mulleri waringensis Sody, 1941
1935-11-07 – Kalimantan (Riam, SW Borneo) – Accipiter trivirgatus microstictus Mayr, 1949
1935-11-14 – Kalimantan (Riam, S Borneo) – Lonchura leucogastra castanonota Mayr, 1938
1935-12-06 – Kalimantan (Kotawaringin, SW Borneo) – Callosciurus prevostii waringensis Sody, 1949
1936-07-20 – Sumatra (Gunung Dempu, S Sumatra) – Pericrocotus miniatus dammermani Neumann, 1937
1936-07-21 – Sumatra (Gunung Dempu, SW Sumatra) – Napothera epilepidota mendeni Neumann, 1937
1936-07-28 – Sumatra (Gunung Dempu, SW Sumatra) – Lanius schach sumatræ Neumann, 1937
1936-08-11 – Sumatra (Bengkulu) – Lariscus insignis diversoides Sody, 1949
[1937]
1938-07-03 – Peleng – Haliastur indus permistus Neumann, 1939
1938-07-04 – Peleng – Otus manadensis mendeni Neumann, 1939
1938-07-08 – Peleng – Dicrurus hottentottus banggaiensis Vaurie, 1952
1938-07-12 – Peleng – Halcyon coromanda pelingensis Neumann, 1939
1938-07-15 – Peleng – Oriolus chinensis stresemanni Neumann, 1939
1938-07-15 – Peleng – Rattus koopmani Musser & Holden, 1991
1938-07-17 – Peleng – Scissirostrum dubium pelingense Neumann, 1939
1938-07-19 – Peleng – Rattus rattus pelengensis Sody, 1941
1938-07-20 – Peleng – Turnix sylvatica kinneari Neumann, 1939
1938-07-31 – Peleng – Rhinomyias colonus pelingensis Vaurie, 1952
1938-08-02 – Peleng – Gerygone fusca intercedens Neumann, 1941
1938-08-08 – Peleng – Alisterus amboinensis versicolor Neumann, 1939
1938-08-08 – Peleng – Chalcophaps indica nana Neumann, 1941
1938-08-08 – Peleng – Megapodius nicobariensis perrufus Neumann, 1939
1938-08-08 – Peleng – Pachycephala melanura pelengensis Neumann, 1941
1938-08-17 – Peleng – Coracina schistacea petersi Neumann, 1939
1938-08-17 – Peleng – Rallus torquatus simillimus Neumann, 1939
1938-08-17 – Peleng – Tarsius fuscus pelengensis Sody, 1949
1938-08-22 – Peleng – Tyto rosenbergi pelengensis Neumann, 1939
1938-08-24 – Peleng – Turdus (Geokichla) mendeni Neumann, 1939
1938-09-24 – Sula (Taliabu) – Artamus monachus sulaensis Neumann, 1939
1938-10-02 – Sula (Taliabu) – Macropygia amboinensis sedecima Neumann, 1939
1938-10-08 – Peleng – Aplonis mysolensis persimilis Neumann, 1941
1938-10-11 – Sula (Taliabu) – Rhipidura teijsmanni sulaensis Neumann, 1939
1938-10-13 – Sula (Taliabu) – Caprimulgus macrurus jungei Neumann, 1939
1938-10-14 – Sula (Taliabu) – Columba vitiensis mendeni Neumann, 1939
1938-10-20 – Sula (Taliabu) – Tyto nigrobrunnea Neumann, 1939
1938-10-22 – Sula (Taliabu) – Phalanger celebensis mendeni Feiler, 1978 [not seen]
1938-10-23 – Sula (Taliabu) – Rattus elaphinus Sody, 1941
1938-11-19 – Sula (Taliabu) – Zosterops atrifrons sulaensis Neumann, 1939
1939-05-10 – Sulawesi (Gorontalo) – Tarsius supriatnai Shekelle, Groves, Maryanto & Mittermeier, 2017
1939-09-03 – Togian (Una-una) – Macropygia amboinensis atrata Ripley, 1941
1939-10-24 – Sulawesi (Menado) – Sciurillus murinus griseus Sody, 1949
1939-11-29 – Togian (Malenge) – Rattus concolor malengiensis Sody, 1941
1939-12-02 – Togian (Malenge) – Rattus sapoensis Sody, 1941
1939-12-03 – Togian (Malenge) – Cynopithecus togeanus Sody, 1949
1939-12-10 – Togian (Malenge) – Malacocincla celebensis togianensis Voous, 1952
1939-12-14 – Togian (Malenge) – Rattus biformatus Sody, 1941
1939-12-17 – Togian (Malenge) – Phalanger ursinus togianus Tate, 1949
1939-12-23 – Togian (Malenge) – Babirussa babyrussa togeanensis Sody, 1949
Compiled the data I have with regards to Menden where mentioned as collector of unspecified name-bearing type material/or holotype of tetrapod nominal taxa in their original descriptions. As it turns out, they concern mammals and birds exclusively (not mentioned by name at least for reptile and amphibian taxa). It is possible to trace his collecting trips through the published dates (without exception complete as to dd-mm-yy).
But please note that the list is not complete (e.g., with the earlier mentioned Hemiprocne longipennis mendeni missing), taking into account only holotype data (i.e., not paratypes), nor is (subsequently) published non-type material taken into consideration here.
And with the caveat that the dates for Hemiprocne comata stresemanni Neumann, 1937 and Aplonis mysolensis persimilis Neumann, 1941 as published may require scrutiny, as at face value the dates do not seem to line up too neatly with the other dates from those far-flung respective localities.
It would seem that in the first years (1927-1929, 1931) he collected mostly in West Java, with one from East Java (Pachycephala pectoralis javana Hartert, 1928).
In 1934, he collected in Sumatra (province Palembang in June, and Lampung in August).
In January 1935, he collected in the Mentawai Archipelago off W Sumatra (only the island Pagai Utara mentioned).
In June-July and November-December 1935, he collected in SW Kalimantan.
In July and August 1936, he collected in Sumatra (provinces Sumatera Selatan and Bengkulu).
In July-August 1938, he collected in Peleng.
In September-November 1938, he collected in the Sula Islands (Taliabu Island only mentioned).
In 3 September 1939, he collected in Togian (Una-una Island).
In 24 October 1939, he collected in Sulawesi (province Menado).
In late November-December 1939, he collected in Togian (Malenge Island only).
I have no results for dates after 23 December 1939. So it would seem that he went out with the proverbial big bang, as he then collected the holotype of the Togian Babirusa. This taxon is now considered by some authors (Meijaard & Groves, 2002, Asian Wild Pig News 2 [1], pp. 9-10) to represent a species in its own right.