ON THE ANATOMY OF THE EURYL^EMID^E. 141 



The nature of the syrinx was the most interesting question to be 

 examined in these specimens, Miiller's short allusion to that of Corydon, 

 quoted above, being all that was known as regards its structure. 



In Eurylcemus ochromelas the syrinx is less specialized, as regards its 

 cartilaginous constituents, than in Cymbirhynchus, and will therefore here 

 be described first. 



The tracheal rings have their usual complete form, being notched 

 before and behind to varying extents, and separated only by narrow 

 intervals. The strong sterno-tracheales, the only extrinsic syringeal 

 muscles, are inserted on the last ring but five. Only the last two tracheal 

 rings are modified. The penultimate ring is narrowed and slightly pro- 

 duced downwards in front ; the last is also narrow, and closely apposed 

 to the penultimate, the membranous interval between the two being 

 very much reduced, except in the middle line in front, where it is well ** z< s - 

 developed, the last ring being here notched above. Behind, the ultimate 

 and penultimate rings are united by a vertically disposed median bar. 

 The last ring forms a three-way piece, there being a forwardly-directed 

 narrow pessulm developed from its hinder margin below. The pessulus 

 is apparently membranous, in this specimen at least, except at its base. 

 The first bronchial semirings are still narrower than the last tracheal one 

 and strongly arched, being concave downwards. They are separated by 

 a very slight interval indeed from the last tracheal ring (three-way piece), 

 and are nearly in contact with each other in front in the middle line ; 

 behind they are inturned and somewhat thickened. To the middle of each 

 ring, or a little posteriorly to this point, is attached the lateral tracheal 

 muscle, which is extremely slender and hardly visible when dry. The 



Fig. 2. 



Syrinx of Eurylamus ochromelas, x 5, viewed from in front. 

 p, the " pseudo-ring." 



second bronchial semirings are shorter than either the first or third ; 

 they are slightly deeper than the first pair, but are narrowed behind. 

 Being only slightly concave downwards, a considerable membrane-covered 

 fenestra is left between them and the first pair. What at first looks 

 like a bronchial semiring is interposed between what are here described 

 as the first and second of that category. This pseudo-ring is most 



