GRUES 



373 



them. The palatines are abruptly truncated posteriorly, as 

 in the herons.' There are small occipital foramina. 



An abnormal member of the crane ^ group is the South 

 American seriema, of which it is usually considered that there 

 are two genera, Gariama and Chung a, of the family Cariamidse. 

 These birds agree with the cranes 

 in possessing an aftershaft and in 

 the number of their rectrices 

 (twelve) . The oil gland, however, 

 is nude. In the pterylosis (which 

 has been described by Nitzsch) 

 there is a marked break between 

 the posterior forks of the anterior 

 section of the dorsal tracts and the 

 anterior fork of the posterior sec- 

 tion of the same tracts. 



The dorsal tract is single on 

 the neck and divides interscapu- 

 larly. The posterior parts of the 

 ventral tract are formed of two 

 rows about two feathers wide. 

 Each joins the outer branch above 

 by one row of feathers merely. 



The skull (fig.. 182) is des- 

 mognathous, but the two maxillo- 

 palatines, though they come into 

 contact in the middle line, are not 

 fused. The nasals are appa- 

 rently holorhinal, really schizo- ^.^^ i82.-Skull of Chunga 

 rhinal (see p. 144), and there are no Ventkai View. (Aetek Beddabd.) 

 basipterygoid processes. There are ^' i"^*""^ ' "' ™p--^"^' "'^^^■ 

 fifteen cervical vertebrce ; five ribs articulate with the sternum, 

 which is one-notched ; it has the spina externa. 



' Stress has been laid upon this fact and comparison, but a posterior trun- 

 cation of the palatines, nearly as marked, is to be seen in Fratercula arctica 

 and not in some other auks. 



' The skull is described by Pakkek, Tr. Linn. Soc. (2), i. p. 128 ; the 

 general osteology and to some extent the visceral anatomy by Bubmeisier, 



