A rare book for the Tunku, with a contemporary portrait of Sultan Ahmad Taju’din Halim Shah of Kedah
J.C. Moulton, Curator of the Sarawak Museum, published this fourth and penultimate instalment of his comprehensive checklist of Bornean butterflies in 1914, covering the family Papilionidae (swallowtails and whites). The paper consolidates nearly fifty years of collecting and taxonomic work into a definitive species list, while simultaneously mounting a sustained argument against the over-fragmentation of subspecific nomenclature that had become fashionable among European lepidopterists.
Summary
Moulton’s treatment of the Papilionidae is structured around two subfamilies: the Pierinae (whites), for which he recognizes 35 species and 5 subspecies, and the Papilioninae (swallowtails), for which he recognizes 43 species. The Pierine section opens with a useful historiographical survey tracing the growth of knowledge from Snellen van Vollenhoven’s 13 species in 1865 through Wallace, Druce, Distant, Pryer, and Bartlett, to Fruhstorfer’s 45 forms in 1910, before settling on Moulton’s own count of 35. He argues that the list is now “tolerably complete” given that very little of Borneo remains unexplored and that Pierines are too large and conspicuous to have been overlooked (p. 2).
The bulk of the paper is a species-by-species account drawing on the Sarawak Museum collection, with detailed locality data, altitude records, and observations on variation. Moulton introduces diagnostic keys for genera and species—a departure from his earlier parts—and uses these to resolve several taxonomic confusions. Notable among these is his reassignment of Delias glauce from Borneo to Sumatra, confirmed by a letter from N.D. Riley at the British Museum verifying that the type specimen, though labelled “Borneo,” was registered as from Sumatra (p. 9). He also unites Catopsilia crocale and catilla into a single variable species, siding with the “lumpers” against Fruhstorfer’s separation (pp. 25–26).
The most intellectually significant portion of the paper is Moulton’s extended critique of subspecific nomenclature, particularly in the context of the Indo-Malayan region. Using Prioneris clemathe as his example, he proposes a visual notation system (lines of increasing length) to indicate the degree of divergence between subspecies, arguing that the current practice of assigning equal taxonomic weight to all subspecies “obscures rather than illustrates geographical relationship” (p. 14). He contends that forms from the Malay Peninsula, Sumatra, and Borneo are almost invariably much closer to one another than to those in Java, and that the present system falsely implies equal isolation across the region.
The paper closes with a biogeographical analysis of the 43 Papilionine species, demonstrating that only four are peculiar to Borneo, while 35 occur in Sumatra, 33 in the Malay Peninsula, and only 25 in Java. Moulton quotes Wallace’s 1865 observation that Sumatra has a closer faunal relationship to Borneo than to Java, and confirms that this has been abundantly corroborated by subsequent collections, while noting that Wallace’s suggestion of a similarly close Java–Borneo connection is not supported (pp. 33–34).
Key Findings
- 35 Pierine species (40 forms including subspecies) and 43 Papilionine species are recognized for Borneo, representing a reduction from Bartlett’s 1896 count of 61 Papilionines, due to the introduction of subspecific nomenclature and broader views on intraspecific variation (p. 33).
- Only four Papilionine species are endemic to Borneo; 35 are shared with Sumatra, 33 with the Malay Peninsula, but only 25 with Java, confirming the faunal unity of the Sumatra–Borneo–Peninsula block and Java’s relative isolation (p. 33).
- Two new names are proposed: Papilio polytes theseus form ignea (a female form with a large yellow cell spot, single specimen from Kuching) and Papilio antiphates itamputi ab. aperta (two specimens from Kinabalu and Malinau with divided outer black bands) (p. 33).
- The type specimen of Delias glauce Butler, long recorded as from Borneo, was verified by the British Museum as actually from Sumatra, removing the species from the Bornean list (p. 9).
- Papilio memnon memnon (the typical form) is one of the very rare instances where Java and Borneo share the same form while Sumatra has a distinct race (anceus), reversing the usual pattern of Sumatra–Borneo affinity (p. 49).
- Papilio fuscus exhibits a “curious distribution” from the Andamans to the Solomons, absent from Sumatra, Java, and the Philippines, suggesting direct faunal communication between India and Papua via Borneo and Celebes (p. 47).
Conclusion
Moulton’s definitive historical takeaway is that the butterfly fauna of Borneo is now sufficiently well known to be regarded as essentially complete for the larger, more conspicuous families, and that the biogeographical evidence overwhelmingly confirms Wallace’s 1865 insight: the Malay Peninsula, Sumatra, and Borneo constitute a single faunal unit characterized by a specialized Malayan fauna, while Java represents a long-isolated landmass with a more generalized Indian fauna superimposed on its own specialized elements.
Context
- The primary source material is the Sarawak Museum collection in Kuching, supplemented by references to the British Museum, the Raffles Museum (Singapore), and the Tring Museum collections.
- The paper’s historiographical contribution lies in its systematic critique of subspecific over-splitting in Indo-Malayan lepidoptera and its proposal of a graduated notation system to express degrees of taxonomic divergence, an argument that remains relevant to biogeographical methodology.