288 MR. F. K. BEDDARD ON THE VISCERAL [May 1 5 



character recalls the Ardeine syrinx' ; in the Storks the hronchidesmus 

 appears to be invariably complete — that is to say, it extends right up 

 to the point of bifurcation of the bronchi. The syrinx itself is almost 

 completely Ardeine ; the rings are entirely cartilaginous ; there 

 appear to be no traces of ossification anywhere ; there is a well- 

 marked pessulus (fig. 4) ; the bronchial rings are only semirings, and 

 there is therefore a well-developed membrana tympaniformis externa ; 

 the free extremities of each of the bronchial semirings begin to ap- 

 proach each other some little way before the entrance of the bronchi 

 into the lungs, but they do not become whole rings. In all the cha- 

 racters mentioned the syrinx of Balceniceps is distinctively Ardeine, 

 and as clearly unlike any Stork. The only true Stork which is at all 

 markedly abnormal in the structure of the syrinx is Abdimia^ ; in 

 this genus, aud to a much less extent in Xenorhynchus, the first 

 bronchial rings are semirings, and there is therefore a membrana 

 tympaniformis ; but in these two genera the lowermost rings of the 

 trachea are modified in the typically Ciconiine fashion ^ 



The only point, in fact, in which the syrinx of Balesniceps rex is 

 not thoroughly Ardeine is in the absence of a pair of intrinsic muscles ; 

 so far as I am aware, all the Ardeidee, and also Scopus, are charac- 

 terized by the presence of a single pair of muscles. 



A careful examination of the syrinx of Balceniceps, however, does, 

 in my opinion, show traces of a syringeal muscle. On each side of 

 the syrinx, and rather nearer to its posterior than to its anterior 

 border, is a delicate ligament (which is shown rather exaggerated 

 in the drawing, fig. 3, p. 287), running from the first bronchial 

 semiring to one of the last tracheal rings. The occasional degene- 

 ration of muscles into tendons leads me to think that this fibrous 

 band is really a degraded rudiment of the syringeal muscles. 



The facts recorded in the present paper are conclusively in favour 

 of regarding Balceniceps as a Heron and not a Stork. It now 

 remains to be seen how far they are in accord with other observa- 

 tions upon the structure of this remarkable bird. The important 

 discovery by Mr. Bartlett^ of powder-down patches on Balceniceps 

 is evidently in favour of the Ardeine as opposed to the Ciconiine affini- 

 ties of the bird. The value of the evidence must of course be dis- 

 counted by the very irregular distribution of powder-down patches 

 among birds; but in the present case the evidence is of more weight, 

 because it is associated with other characters, all of which point the 

 same way. 



A very detailed study of the osteology of the Balceniceps has led 

 Prof. Parker to the opinion that "its nearest relations are tlie South- 

 American Boatbill {Cancroma cochleuria) and the little South- 

 African Timbre (Scopus umbretta).^' 



' I have figured the hronchidesmus in the syrinx of Scopus (P. Z. S. 1884, 

 p. .t44) ; in liuleeiiicips tlie anterior (free) margin is further away trom tne bifur- 

 cation of the bronchi than in Scopus. 



2 See F. E. Beddard, '^ On the Trachea in certain Storks," P. Z. S. ISSfi, p. 321. 



^ Weldon, "On some points in the Anatomy of FJubnicopttrus and itd allies," 

 P. Z. S. 1883, p. 639. 



* Loo. cit. 



