<Tr> <Td_colspan="2"> <Ul> <Li> Armadillidium affine </Li> <Li> Armadillidium armeniense </Li> <Li> Armadillidium brevicaudatum </Li> <Li> Armadillidium commutatum </Li> <Li> Armadillidium decipiens </Li> <Li> Armadillidium marmoreum </Li> <Li> Armadillidium nitidulum </Li> <Li> Armadillidium oliveti </Li> <Li> Armadillidium pilulare </Li> <Li> Armadillidium schellenbergi </Li> <Li> Armadillidium sorattinum </Li> <Li> Armadillidium subdentatum </Li> <Li> Armadillidium triviale </Li> <Li> Armadillidium variegatum </Li> <Li> Armadillo ater </Li> <Li> Armadillo convexus </Li> <Li> Armadillo marmoreus </Li> <Li> Armadillo pilularis </Li> <Li> Armadillo pustulatus </Li> <Li> Armadillo trivialis </Li> <Li> Armadillo variegatus </Li> <Li> Armadillo vulgaris </Li> </Ul> </Td> </Tr> <Ul> <Li> Armadillidium affine </Li> <Li> Armadillidium armeniense </Li> <Li> Armadillidium brevicaudatum </Li> <Li> Armadillidium commutatum </Li> <Li> Armadillidium decipiens </Li> <Li> Armadillidium marmoreum </Li> <Li> Armadillidium nitidulum </Li> <Li> Armadillidium oliveti </Li> <Li> Armadillidium pilulare </Li> <Li> Armadillidium schellenbergi </Li> <Li> Armadillidium sorattinum </Li> <Li> Armadillidium subdentatum </Li> <Li> Armadillidium triviale </Li> <Li> Armadillidium variegatum </Li> <Li> Armadillo ater </Li> <Li> Armadillo convexus </Li> <Li> Armadillo marmoreus </Li> <Li> Armadillo pilularis </Li> <Li> Armadillo pustulatus </Li> <Li> Armadillo trivialis </Li> <Li> Armadillo variegatus </Li> <Li> Armadillo vulgaris </Li> </Ul> <P> Armadillidium vulgare, the (common) pill - bug, potato bug, (common) pill woodlouse, roly - poly, doodle bug, or carpenter, is a widespread European species of woodlouse . It is the most extensively investigated terrestrial isopod species . </P> <P> Armadillidium vulgare may reach a length of 18 millimetres (0.71 in), and is capable of rolling into a ball when disturbed; this ability, along with its general appearance, gives it the name pill - bug and also creates the potential for confusion with pill millipedes such as Glomeris marginata . It can be distinguished from Armadillidium nasatum and Armadillidium depressum, the only other British species in the genus, by the gap that A. nasatum and A. depressum leave when rolling into a ball; A. vulgare does not leave such a gap . </P>

What is the scientific name for a pill bug