Folia Historico-Naturalia Musei Matraensis - A Mátra Múzeum Természetrajzi Közleményei 21. (1996)

the shortness of the phalanx the CW value can not be measured safely, and this species is best separated from the others by the GL/PW and GL/DW ratios. In the Hobby the proximal end of the bone is relatively wider and the capitulum phalangis is thinner than in the Merlin, and hence the phalanges of the two species can be identified with the help of the PW/DW and GL/DW ratios. The corpus phalangis in both species is more separated from the ends of the bones (the phalanx tapers off) than in the Kestrels. In the Red-footed Falcon the length of the phalanx is quite constant, and the ends of the bone are just slightly wider than the corpus (dorsal view) (Plate XLV, Figures 34-38). In the Kestrel and Lesser Kestrel the phalanx is so short that it looks as it would consist of two ends without a corpus. In the Red-footed Falcon the edge of the proximal end of the bone from the tuberculum extensorium is extends in the same line in lateral direction as the apex of the tuberculum, and it is not waving but straight instead (Plate XLV, Figure 37). The plantar edge of condylus medialis of capitulum phalangis is pointed in the Red-footed Falcon, and almost the same in the Hobby. In the Merlin this part is only slightly or not pointed, and in the Kestrel the condylus medialis in medial view is arch-shaped (Plate XLV, Figures 23-25). In the Red-footed Falcon the depressio epicondylaris medialis and depr. epic, lateralis on the capitulum phalangis are almost impossible to detect, while in the Kestrel they are deep. Summary Falco subbuteo: - the phalanx is long, - the GL/CW ratio is high, can be used for the identification, - the corpus phalangis is well separated from the ends of the bone (dorsal view), - the proximal end of the bone is relatively wider than in the Merlin, - the condylus medialis is pointed on the plantar edge (medial view). Falco columbarius: - the phalanx is relatively long, - the corpus phalangis is well separated from the ends of the bone (dorsal view), - the capitulum phalangis is relatively wider than in the Hobby (dorsal view), - the condylus medialis is not or only slightly pointed on the plantar edge (medial view). Falco tinnunculus: - the phalanx is short and very thick, in dorsal view square, - the GL/PW ratio is low, can be used for the identification, - the corpus phalangis is practically missing, - the condylus medialis is not pointed on the plantar edge, arch-shaped in medial view, - the depressio epicondylaris medialis and lateralis are deep. Falco vespertinus: - tfie thickness of the phalanx is longitudinally very even (dorsal view), - the dorso-lateral edge of the proximal end of the bone is straight (dorsal view), - the condylus medialis is pointed on the plantar edge (medial view), - the depressio epicondylaris medialis and lateralis are almost impossible to detect, or missing. Falco naumanni: - the phalanx is very small, quite short and thick, - the corpus phalangis is practically missing. 63