232 MR. F, B, BHDDABD ON BISStTBA BPISCOPUS. [Feb. 4, 



contrary to what we find in typical Storks (c/. fig. 3, p. 234), the 

 membrana tympaniformis is well developed and the bronchidesmus 

 is incomplete. This Stork, however, agrees with other Storks in 

 the absence of intrinsic syringeal muscles and in the modification 

 of a large number of the last tracheal rings. In looking through 

 the MS. notes left by the late Prof. Garrod, with a view to a 

 forthcoming work upon the Anatomy of Birds, upon which lam at 

 present engaged, I find that the two Storks above mentioned are 

 not the only ones in which the ambiens muscle is absent, A third 

 species, viz. Dissura episccypws, is precisely in the same condition. 

 This bird is often spoken of as Ciconia episcopus; but it seems to 

 me that the anatomical peculiarity referred to justifies its generic 



Syrinx of Dissura episcopus. 



separation — just as Prof. Garrod thought of the species of Xeno- 

 rliynchus which showed the same absence of so characteristic a 

 Oiconiine muscle. 



The discovery of this note reminded me that 1 bad preserved at 

 the time of its death the syrinx of a specimen of Dissura episcopus. 

 On examining this syrinx, I found that it presented quite the same 

 anomaly of structure (from the Ciconiine point of view) as does 

 Ahdimia. It is very interesting to find here also — correlated with 

 the deficient ambiens — a syrinx that approaches the Ardeiue in its 

 characters. In Dissura, however, the bronchidesmus is complete 

 as in the typical Storks ; but the membrana tympanifoi-mis, as 

 may be seen from the drawing exhibited (see fig. 1), is well 

 developed, quite as well as in Ahdimia (see fig. 2, p. 233). 1 need 

 not trouble the Society with a detailed description of the syrinx of 

 the bird, since the accurate drawing shows all its features of interest. 

 It may be generally pointed out that the terminal rings of the 

 trachea are Stork-like as in Abdimia, and that there are no intrinsic 

 muscles ; but that the membrana tympaniformis is Ardeine, with a 

 well-developed pessulus. This is, in my opinion, an additional 

 reason for placing this species of Stork in a genus distinct from 



