ME. W. K. PAEKEE ON THE OSTEOLOaT OF THE KAGU. 



511 



In the Psophia there is one pair of free cervical ribs, and one perfect lumbo-sacral arch ; 

 behind this there is a free styloid rib occasionally on the right side, the left coalescing 

 with the sacrum ; there is one pair of abdominal ribs. In the Kagu there are two pairs 

 of free cervical ribs, and one nearly perfect lumbo-sacral arch (PI. XCI. fig. 1) ; there 

 is no abdominal rib. In the Eiiri/jyi/ga the cervical ribs are all ankylosed to the ver- 

 tebi-jc; there is one perfect lumbo-sacral arch, small free ribs to the second of that 

 series, and a veiy small abdominal rib on each side. In Botaurus viridis there are free 

 ribs to the last two cervical vertebi-ae, a nearly perfect lumbo-sacral arch, and a pair of 

 styloid abdominal ribs. 



In the Anthropo'ides stanleyamis there are two pairs of free cervical ribs, three pairs 

 of lumbo-sacral ribs, the last of which is apt to become ankylosed to the sacrum. 



In the Balearic Crane there is only one arch developed from the lumbo-sacral region, 

 and it is perfect ; but in Grus antigone two pairs of such arches exist, and a pair of styloid 

 floating ribs behind them. 



In the Kagu, the Psophia, and the Eurypyga the first four dorsal ribs are ankylosed 

 together; in Grus antigone the last cervical and first two dorsal blend together; in 

 Balearica pavonina the first two dorsals only, whilst the Stanley Crane agrees with the 

 Bittern and the Heron in having these bones free of each other — at least for some 

 years. 



The last caudal vertebra may, at least, count for seven (it is composed of ten in the 

 Duck) ; and thus the number six ought to be added to the seven caudal. We may thus 

 make a numerical comparison of the whole series as follows : — 



Total Nr. of Tertebrse. 



PsopJna crepitans 53 



Bhlnochetus juhatus 49 



Ewypyga helias 49 



Botaurtts viridis 43 



Anthropdides stanleyamis 54 



These numerical comparisons are of considerable interest, thus : — We see that the 

 Eurypyga and the Kagu have the same total number of vertebrae, although they are 

 disposed of differently, that the Psophia differs but little from the typical Cranes, that 

 the dorsal vertebrse are more confluent in the aberrant Gruine forms than in the types, 

 and that this character is not constant in the typical genera. 



VOL. VI. PART Vni. 4 B 



