Of all the several hundred thousand butterflies in the collection there are some very special ones: the ‘types’.
When ever a new species of animal or plant is found it has to be given a name, described and published so that anyone else can recognise it. The original specimen or specimens used to describe a species becomes the unique reference example of that species. They are the fundamental physical example of a taxon. Describing a species or other taxon is part of scientific nomenclature upon which the biological and geological sciences hinge. Without them there would be chaos.
In the example shown Siderone marthesia cancellariea the specimen No. 1008 of the museum’s collection is the holotype for that subspecies, published by A. Hall in the Entomologist in 1935 and caught in St. Anns, Trinidad, January 1943. A precise set of rules are laid down by the International Commission on Zoological Nomenclature that govern the naming of species.
To confuse things there are different types of type (!). Simply speaking a single specimen might be described and this is the holotype (the main type), but additional specimens might also be mentioned and described within the description of the species. These are termed cotypes. Two or more specimens might be used to describe a species neither of which being defined as the holotype – these become syntypes. Types can be lost and another specimen is described in its place – the neotype. And there are yet other ‘types’.
Work currently undertaken at the Booth involves listing, checking and photographing all of the butterfly types in order to prepare an on-line catalogue so people know what important specimens we have. With over 600 specimens and over 200 taxa to work through this is quite a job.