1880.] ANATOMY OF PASSERINE BIRDS. 383 



Both the species under discussion agree entirely with Psarisornus 

 and Serilophus in the points already noted by Prof. Garrod. I may 

 add that the pectoralis primus is large, as is also the pectoratis 

 secundus, this muscle extending to the end of the sternum, or there- 

 abouts. As in other Passeres, the biceps-sW^ to the patagium and the 

 expansor secundariGrum are absent. The semimembranosus is slender, 

 but muscular. The gluteus primus is large, covering the biceps ; 

 and the obturator interniis is elongatedly oval. As will be seen in 

 fig. I, in Cymbirhynchus the vinculum in the deep plantar tendons 

 is strong, and has the character of a firm round tendon, instead of 

 being composed of more or less transversely-directed fibres running 

 between the two tendons, as in many birds where this structure 

 obtains. In Eurylcemus ochromelas it is apparently double, there 

 being a second additional slip given off lower down from the hallus- 

 tendon, which joins the tendon of the digital flexor at the point 

 where the latter, splitting up into three, receives the main vinculum. 



As regards the alimentary canal of these birds, there is nothing 

 unusual in its conformation. The tongue is elongatedly cordate, and 

 slightly bifid at the tip. Both it and the palate generally are smooth ; 

 along its posterior sides_ it is provided, as is frequently the case, 

 with about eighteen small, backwardly directed, spiny processes, 

 that at the angle being much larger than the others. There is no crop 

 developed ; and the jwoventriculus is zonary : in Cymbirhynchus it 

 is f, in E. ochromelas \ inch in vertical depth. The stomach has the 

 character of a not very muscular gizzard, and is lined with hardened 

 brown epithelium; the left lobe of the liver is the smallest (consi- 

 derably). The caeca are present, as might have been predicted from 

 the nude oil-gland^, and are truly Passerine in nature, being mere 

 nipples g, or, in the smaller species, y'jj inch long. The following are 

 the intestinal measurements : — 



Cymbirhynchus. Small intestine 7 fin., large intestine 1^, total 9 in. 

 E. ochromelas. „ 5f „ „ |, „ 6^ in. 



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

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

 Corydon, quoted above, being all that was icnown as regards its 

 structure. 



In Eurylcemus ochi-omelas the syrinx is less specialized, as regards 

 its cartilaginous constituents, than in Cymbirhynchus, and will there- 

 fore 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 

 shghtly produced 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, 



^ Cf. Garrod, P.Z. S. 1874, p. 119. 



