Contributions to Bird-Anatomy and Classification. 21 



In Carpophaga latrans the stomach is even more peculiar ; 

 for here the epithelial lining of the gizzard is developed 

 into about two dozen horny conical processes, like the tu- 

 bercles of a Cidaris or similar Sea-urchin. A similar con- 

 dition has been described by MM. Verreaus and Des Murs 

 in C. goliath of New Caledonia*; but no other species 

 of Carpophaga yet examined shows any trace of such a 

 structure. 



5. Psittaci-f. — In these papers, as in the last, the condition 

 of certain structures is recorded in a large number of forms, 

 and from the combinations of characters so obtained a scheme 

 of classification is sketched out, each group having assigned 

 to it a formula stating its most essential characters. The 

 jDresence or absence of the ambiens muscle, of a furcula, and 

 of an oil-gland are the points here laid stress on, together 

 with the condition of the carotid arteries. Of these there 

 may be either two normally situated, or only one, the left 

 [Cacatua and Licmetis tenuirostris) , or two, ih.eleft of which, 

 instead of running with its fellow in the hypapophysial canal, 

 as already explained, runs superficially up the neck with the 

 left vagus nerve and jugular vein. This last condition, which 

 obtains in no other birds, is considered, as I think rightly, suffi- 

 ciently important to divide off as a main group of Psittaci 

 all those possessing it — a group including all the American 

 Parrots, together with the Platycercidae (including Lathamus) , 

 Nestor, Dasyptilus, and the African Parrots, other than Aga- 

 pornis and Palaornis, of the Old- World forms. The further 

 subdivision of these groups is effected in the way already 

 indicated. In a supplementary note attention is called to the 

 probably invariable presence of a gall-bladder in theCacatuince, 

 though this organ has not been found in any other Parrots. 



* Tliis lias lately been described at greater length and figured by M. 

 Viallane (Ann. Sc. Nat. ser. 6, Tii. art. no. 12). 



^ " On Points in the Anatomy of the Parrots which bear on the Clas- 

 sification of the Suborder," P. Z. S. 1874, pp. 586-598, pis. Ixx., Ixxi. 

 " Notes on the Anatomy of certain Parrots," P. Z. S. 1876, pp. 691, 692 ; 

 " Note on the Absence or Presence of a Gall-bladder in the Family of 

 the Parrots," P. Z. S. 1877, p. 793. 



