fj^unspecified, Alp^eyD flies have but three tarsal joints.

Basitarsus broadened distally and incompletely separated from second tarsal segment owing to interruptions of the intersegmental membrane. Polarity of bract-bristle arrangement locally reversed in regions of membrane gaps (FBrf0029371). 27-48 sex-comb teeth disposed in more-or-less parallel longitudinal rows in males; number of transverse-bristle rows increased in females (FBrf0018995). Extra leg joints tend to form as mirror-image duplications proximal to the normal joint between the first and second tarsal joints (FBrf0045354). Clones of Alp⁺ tissue in Alp^eyD/+ background exhibit Alp^eyD/+ phenotype (FBrf0018995), but both Alp⁺leg discs transplanted into Alp^eyD hosts and the reciprocal transplant develop autonomously (FBrf0019415). RK2.