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Show 286 MR. W. P. PYCRAFT ON THE [Mar. 17, x . S u m m a r y . The isolated position of the Cuculiformes among the Coracio-morphae is as evident from a study of the osteology of the group as from other points of view. Their nearest allies, judged from an osteological standpoint, would appeal* to be the Coraciidae (Coraciince and Leptosomatince) and Bucconidae on the one hand, and-more remotely-the Opisthocomi on the other. Their relationship to the Psittaci, which is generally agreed upon, would, I think, never be suspected from a comparison of the skeletal framework. This fact is probably to be explained by the great amount of specialisation which the Parrots have undergone. Concerning the association of the Cuculiformes with the Bucconidae, a few words of explanation are necessary. Although this connection has several times been made by the older ornithologists, Fiirbringer appears to be the only modern systematist who, on anatomical grounds, takes a similar view. Gadow (3 ) regards the Bucconidae as close allies of the Galbulidae, placing the two in the same family-Galbulidae. Beddard, on the other hand, widely separates these two forms, and I think rightly so. He places the Bucconidae between the Pici and the Rhamphastidae, but remarks that this is a family which " is at present little known, and whose affinities are therefore doubtful. It is only provisionally that I place them in the present position." The claims to relationship, of the group now under consideration, to the Opisthocomi are, on osteological grounds, not at first sight very strong. A careful study, however, of the skulls of Cuculi and Musophagi, and a comparison with Opisthocomus, will show points of agreement which suggest affinity rather than convergence. The Musophagi most nearly approach Opisthocomus. The pelvis and sternum of Opisthocomus are Cuculine. That the Cuculidae and Musophagidae are very near allies there can be no doubt. Indeed, the relationship between these two is the only relationship about which we can speak with any real certainty. According to the British Museum Catalogue of Birds, vol. xix., the Cuculidae (suborder Cuculi) embraces 47 genera and includes 202 species grouped under 6 subfamilies. This scheme is the work of Capt. Shelley. Beddard (1 ) recognises only 3 subfamilies, and these, I think, will be found to meet all demands. Further, it is quite open to question whether even these should not be regarded as groups a, 6, c, rather than subfamilies. Osteologically, the Cuckoos vary far more widely in respect of the pelvis and sternum than in any other character. The great feature in the skull is the uniform plan of the palate. Trusting to this alone, one might divide the Cuckoos into two groups__ Coua in the one, and all the rest of the Cuckoos in the other: yet the difference in the two palates is trivial. The only other characters offered the systematist to choose from a,re the form of the lachrymal and temporal fossae and the shape of the beak, |