40 Southern Cross. 



Skulls. 



In the tabular records will be found the principal dimensions of 

 the skulls brought home by the * Southern Cross,' to which are added 

 for purposes of comparison similar details of those collected by the 

 ' Belgica,' as well as of the specimens contained in the collection of the 

 British Museum. The only specimens, of which we know the sex 

 from examinations made in the flesh, are those collected by the 

 Belgian expedition. These are therefore arranged according to 

 their sex, the males first, and each sex in order of size from largest 

 to smallest. The British Museum specimens are arranged simply in 

 order of size, as are also those brought home by the ' Southern Cross! 

 The numbers attached to the latter are simply those which were 

 placed upon them in order to prevent confusion when first received. 

 They have no other significance, but a knowledge of these facts will 

 probably be of interest to the authorities of the various museums into 

 whose hands they may find their way.^ 



Distinguishing characteristics. — The skull of this species is well 

 known, so that a detailed description is uncalled for. Although not 

 possessing the enormous dimensions of that of Ogmorhinus, it may 

 be at once distinguished at all ages from that of any other species by 

 the peculiar cheek-teeth. These are both large and remarkable for 

 the complicated arrangement of their cusps. As in Ogmorhinus, 

 there is a principal central cusp, but this is supported, not by two 

 others, one anterior, the other posterior, but by one quite small cusp 

 in front, and by from one to three behind. The central cusp is far 

 larger than the remainder, and its apex is usually bulbous ; all 

 have a tendency to point backwards. In addition to these dental 

 characters, the skull of this species differs from that of Lcidonychotcs, 

 which it approximately equals in size, in its longer palate, and 

 longer, broader, anterior portion,- as well as in the shape of the lower 

 jaw. This is in Lobotlon far deeper, stronger, and more massively 

 built than in Leptonychotes. 



Sex. — An attempt has been made in the " Table " of dimensions 

 to determine the sex of each specimen, both in the case of the 

 * Southern Cross ' and the British Museum collections, from the data 

 supplied by those collected by the members of the Belgian expedi- 



' Doubtless all the specimens collected by Mr. Hanson were fully described in 

 his notes, and could have been identified, if these notes had been properly cared for 

 after his death. 



