CHIONIS MINOR. Ill 



of the zone of glands as a whole, since it %'aries widely in closely-allied 

 genera. 



The gizzard appears to b6 unique, so far as we know, in the antero- 

 posterior, instead of lateral disposition of its masses of muscle. The 

 development of muscle is intermediate between the great masses found 

 in the Rasores (and such Natatores as the goose) and the less considerable 

 layers found in Grallatores, but altogether different from the thin mem- 

 branous bags of fish-eating birds like gulls. The length of the intestine 

 (about three times that of the bird), and its calibre, do not differ greatly 

 from the same characteristics in Rasores. The caica are very long, and 

 dilated toward their blind ends ; in this respect totally unlike the gral- 

 latorial type, in which the cceca, when present, are commonly small and 

 simple. 



The third caecum, of uncertain significance, is distinct, although small. 

 This appendage is found in various grallatorial, some struthious, and 

 many other birds. On the whole, it is safe to say that the digestive canal 

 is decidedly rasorial in character. 



OSSEOUS SYSTEM. 



From a decided position among GaUhue, on the other hand, certain 

 parts of the skeleton exclude this bird as effectually as the existence 

 of a sternal keel renders the consideration of struthious affinities un- 

 necessary in this connection. The sternum departs furthest from that 

 of a struthious bird, and next most widely from the very peculiar raso- 

 rial form. The most cursory inspection throws out at once the deeply- 

 cleft, strongly specialized sternum of gallinaceous birds. It is of a very 

 simple generalized type, presenting characteristics to be found in widely 

 diverse groups of birds, but on the whole resembles most closely the 

 commonest form of the sternum of the Laridce, with a marked likeness 

 also to the breast-bone of a plover. The obvious resemblance of this 

 bone to that of Hicmatopus is the central point of De Blainville's argu- 

 ment. Yet we are inclined to believe that the sternal characters upon 

 which De Blainville most relies as distinctively pluvialine are simply 

 the most generalized features of the bone — those Avhich, under various 

 modifications, are to be found in the greatest number of different groups. 

 And simple comparison shows beyond dispute a greater resemblance 

 of this sternum to that of the gulls than to that of wading birds. 



The general form, the existence of a prominent manubrial process, 

 the width and extent of the costal marg-ins, the great prolongation of 



