174 MR. W. A. FORBES ON THE GENUS LATHAMUS. [Feb. 18, 



pelvis is wider, the preacetabular part much shorter, and the iliac 

 fosssB shallower and smaller. These differences will be visible from 

 the figures which I exhibit (PL XVI. figs. 11, 12), in which are 

 shown respectively the pelvis of Lathamus and of Lorius tricolor. 



As regards internal anatomy, little can be said of any important 

 characters, except the difference in the disposition of the carotid 

 arteries in the two groups, first pointed out by Prof. Garrod, and 

 already mentioned above. The nature of the tongue in Lathamus 

 requires reexamination, as also does the coloration of the eyes, this 

 presenting very marked characteristics in all those Triehoylossince I 

 have been able to examine alive (of the genera Lorius, Eos, Chalco- 

 psitta, and Trichoglossus), and being quite unlike that prevalent in the 

 Platycerci and most other Parrots. 



In coloration Lathamus is no doubt aberrant, but is no more 

 clearly related, as far as I can see, to one group rather than the other. 

 The external rectrices being blue is perhaps a hint of its Platycerciue 

 relations. 



To conclude, the more important characters of Lathamus, i. e. 

 pterylosis and superficial left carotid, beak, nostrils, cere, feet, skull, 

 and pelvis, all point to a near relationship to Psephotus, Plati/cercus, 

 and allied genera. The abnormal tufted tongue, the retention of the 

 furcula, and the sharp pointed wings may be regarded as adapta- 

 tions to its tree- and flower-loving modes of life, and not as due to any 

 consanguinity with the Trichoglossinae. Lathamus may be a more or 

 less modified remnant of a group that branched off from the common 

 stock with the progenitors of the more typical Platycerci, and of 

 which all the others have become extinct (perhaps due to the com- 

 petition with the more specialized Trichoglossince) ; or it may be a 

 member of the Platycerciue group that has become specialized to 

 modes of life like those of the true Lories and Lorikeets, and so has 

 come to resemble them in some few superficial particulars. 



EXPLANATION OF PLATE XVI. 



Figs. 1, 2. Back and side views of Lathamus discolor, showing pterylosis. 

 3, 4. The same of Platycercus pcnnantii. 

 5, 6, The same of Trichoglossus concinnus. 



7. Mandible, deprived of horny sheath, of Eos rubra. 



8. The same of Lathamus discolor. 



9. Skull, seen from above, of Eos rubra. 



10. The same of Lathamus discolor. 



11. Felyis of Lorius tricolor. 



12. The same of Lathamus discolor. 



