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Show 376 DR. ST. G. MIVART ON CANINE [May 6, The agreement in size and structure of the different examples of each of the bones leads to the conclusion that most of them belong to one species of bird, and it was thought at first they might be parts of a small Tern ; but the curved beak, as well as the longer and more slender tarso-metatarse, seems to indicate a closer affinity with the Petrels. Possibly these remains will be found to belong to some species now living on the western coasts of South America, although the nitrate districts are said to be, at the present time, almost devoid of animal life and the birds from which these fossils are derived must have existed in the district in considerable numbers. Mr. H . Seebohm kindly suggested a reference to Mr.H.A.Forbes's memoir on the ' Challenger' Petrels as likely to help in the comparison of these remains; and in that memoir (Memorial Volume, p. 426) measurements are given of the limb-bones of several forms, including those of Cymochorea leucorrhoa, the latter agreeing so closely with the measurements of the fossils as to render it highly probable that they are generically allied. At present, however, I have been unable to get a skeleton of any species of this genus for close comparison. The ' Challenger ' specimen of Cymochorea leucorrhoa seems not to be in the British Museum collection. Mr. O. Salvin, w h o is so well acquainted with the Petrels, tells me that C. leucorrhoa is not known on the west coast of S. America; but is there replaced by a closely allied species which he has described (Proc. Zool. Soc. 1883, p. 430) and named C. markhami. Two skins of Mr. Salvin's species are in the British Museum, and by the kindness of M r . Bowdler Sharpe I have been able to examine them; but the only parts which can be compared are the beak and the length of the tarso-metatarse, and in so far as one can judge of parts which are still enclosed in their horny coverings, they seem to agree with the Peruvian fossils. The peculiarities of structure presented by these fossil bones agree so nearly with those of forms closely allied to Cymochorea, and their proportions and absolute lengths agree so well with the measurements of C. leucorrhoa, that it is highly probable they will prove to belong to the genus Cymochorea and to be closely allied to C. leucorrhoa and C. markhami, but the want of skeletons for detailed comparison prevents a more definite determination. 5. Note on Canine Dental Abnormalities. By Dr. ST. G. MIVART, F.R.S. [Received April 25, 1890.] It appears to m e that it may be useful to record some dental abnormalites amongst the Cauidae which I have myself observed or have found noticed by others. In his recent paper * Dr. Windle has enumerated, with respect to Domestic Dogs, 7 cases of an additional 1 P. Z. S. 1890, p. 29. |