Scarce swallowtail Scarce swallowtail The scarce swallowtail ("Iphiclides podalirius") is a butterfly belonging to the family Papilionidae. It is also called the sail swallowtail or pear-tree swallowtail. Subspecies include: "Iphiclides podalirius feisthamelii" is sometimes treated as a valid species, "Iphiclides feisthamelii". Despite the name "scarce swallowtail", this species is quite common. The scarcity of United Kingdom migrants is responsible for the English vernacular name. This species is widespread in the East Palearctic ecozone and in most of Europe with the exception of the northern parts. Its range extends northwards to Lower Lusatia and central Poland and eastwards across Asia Minor and Transcaucasia
Comma category difference between the two notions is that a natural transformation is a particular collection of morphisms of type of the form formula_182, while objects of the comma category contains "all" morphisms of type of such form. A functor to the comma category selects that particular collection of morphisms. This is described succinctly by an observation by Huq that a natural transformation formula_183, with formula_184, corresponds to a functor formula_185 which maps each object formula_8 to formula_187 and maps each morphism formula_188 to formula_16. This is a bijective correspondence between natural transformations formula_181 and functors formula_185 which are sections of both