406 Mr. R. Lydekker on 



allies, it appears to the present writer, after careful exami- 

 nation, that the original determination of Mr. Konig was 

 much more nearly correct than the one subsequently ad- 

 vanced, and that the genus should probably find a place near 

 the Larida. The whole form of the skull is, indeed, essen- 

 tially Laroid, and quite unlike that of the Kingfishers ; and, 

 although Sir R. Owen was right in referring to the absence 

 of distinct supraorbital grooves, yet, as there are traces of 

 such grooves, we cannot on this account remove the genus 

 from the Gavise, more especially as we might well expect to 

 find these grooves less developed in an early ancestral type. 

 Moreover, while a Kingfisher would not be the kind of bird 

 whose remains we should expect to meet with in the Sheppey 

 deposits, we should naturally look therein for the bones of 

 Gulls. That Gulls did occur in those beds is proved by the 

 distal extremity of a humerus in the British Museum, which 

 exhibits the deep depression on the palmar aspect of that 

 part of the bone, and also the point of attachment of the 

 ectepicondylar process ; both of which structural features are 

 absolutely characteristic of the Larine humerus. And since 

 there is the further probability that this Larine humerus 

 may actually have pertained to Halcyornis, with the skull of 

 which it agrees in relative size, we shall certainly be justified 

 in placing that genus near the Gavise. 



Other imperfect bones of Carinate birds, such as the 

 sacrum figured on page 553 of Owen^s ' British Fossil 

 Mammals and Birds,^ have been obtained from Sheppey, 

 although none of those which have come under the au thorns 

 notice are sufficiently well preserved or sufficiently charac- 

 teristic to admit of the determination of their affinities. 

 With the exception of the presumably Accipitrine genus 

 Lithornis, the remains of which might well accompany those of 

 truly estuarine birds, all the birds yet known from the old 

 Eocene estuary of the Thames region are precisely those 

 which we should expect to meet with in deposits o£ the 

 nature of those of Sheppey. Thus the Gannets and Cormo- 

 rants of the present day were represented by the gigantic 

 Argillornis and the smaller Odontopteryx, while the place of 



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