A good number of Polybothris acquired a strange form, similar to a long and narrow ellipse, with an arcuated body (side view). This form is usually named "navicular" (from Latin "navicula" = small ship). Polybothris navicularis can be considered the "type species" of this group. We can see some of these species:

Polybothris navicularis	Polybothris impressipennis	Polybothris humeralis
Polybothris semipolita	Polybothris zivetta	Polybothris zivettoides
Polybothris quadriplicata		Polybothris viriditarsis