376 DR. ST. G. MIVART ON CANINE [May 6, 



The agreement in size and structure of the diiferent 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 com- 

 parison 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, who 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 Mr. 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 measure- 

 ments of C. leucorrhoa, that it is highly probable they will prove to 

 belong to the genus Cymochorea and to be closely allied to C. 

 leucorrJioa 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 me that it may be useful to record some dental 

 abnormalites amongst the Cauidse 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 



> P. Z. S. 1890, p. 29. 



