Swallowtail butterfly Swallowtail butterfly Swallowtail butterflies are large, colorful butterflies in the family Papilionidae, and include over 550 species. Though the majority are tropical, members of the family inhabit every continent except Antarctica. The family includes the largest butterflies in the world, the birdwing butterflies of the genus "Ornithoptera". Swallowtails have a number of distinctive features; for example, the papilionid caterpillar bears a repugnatorial organ called the osmeterium on its prothorax. The osmeterium normally remains hidden, but when threatened, the larva turns it outward through a transverse dorsal groove by inflating it with fluid. The forked appearance of the swallowtails' hindwings, which
Comma category functors out of the product category formula_97. For each comma category there are forgetful functors from it. Several interesting categories have a natural definition in terms of comma categories. Limits and colimits in comma categories may be "inherited". If formula_1 and formula_2 are complete, formula_145 is a continuous, and formula_146 is another functor (not necessarily continuous), then the comma category formula_6 produced is complete , and the projection functors formula_148 and formula_149 are continuous. Similarly, if formula_1 and formula_2 are cocomplete, and formula_152 is cocontinuous, then formula_6 is cocomplete, and the projection functors are cocontinuous. For example, note that in